Learning outcomes: Apply the design thinking process to design a simple application to solve a current problem. (so basically, just know the process and definitions) Quick background on design thinking: ? Definition of design thinking according to Wikipedia: o “Design thinking is a method for the practical, creative resolution of problems using the strategies designers use during the process of designing. Design thinking has also been developed as an approach to resolve issues outside of professional design practice, such as in business and social contexts.” (Wikimedia Foundation, 2018 ) ? Design thinking takes the following into consideration: o Usefulness- functionality o Usability- ease of use o Desirability- appealing, status ? “Left brain” fields (uses feelings, imagination rules, fantasy based, etc) are combining with “right brain” fields (uses logic, facts rules, reality based, etc) to advance human experience, or in this case enhance the design thinking process.
(University of pretoria: Department of Informatics, 2018)
Design thinking process: (important) 1) Empathy: ? “The capacity to recognize emotions that are being experienced by another sentient or fictional being” (Wikimedia Foundation, 2018 ) ? Empathy is the foundation of a human-centered design process. To empathize, we: o Observe: View users and their behaviour in the context of their lives. o Engage: Interact with and interview users through both scheduled and short “intercept” encounters. o Immerse: Experience what your user experiences ? Next you decide what problems you want to resolve (poverty, corruption, etc). Then you agree on who the audience is (government, businesses, society, etc). After you collected this information you must record it on paper or video. Also add the priority of the project in terms of urgency and create a list of items that will make the project successful.
2) Research: ? “A formal process of using meetings, interviews, questionnaires, sampling and other techniques to collect information about problems, requirements and preferences.” Also called information gathering or data collection. ? Materials: ? The internet. Search for existing forms, documentation and databases. ? Papers for: questions, rich pictures. ? Drawing rich pictures: review the history of the issue then collect examples of other attempts to solve the same issue. Then talk to your end-user, that brings you the most fruitful ideas for later design. Remember to record the information on paper or video.
3) Ideation ? To ideate is to form or have an idea. ? 5 key processes in ideation: 1) Identify the needs and motivations of your end-users. 2) Generate as many ideas as possible to serve these identified needs. 3) Log/record your brainstorming session. 4) Don’t judge or debate ideas. 5) During brainstorming, have one conversation at a time. ? Use materials such as paper to record each person’s idea. ? Identify the needs and motivation of your end-users. ? Generate as many ideas as possible to serve these identified needs. Don’t judge or debate any ideas. ? Discuss and expand on the ideas of others. Then expand your rich picture by including information gathered from your research phase. ? Remember to record your findings on paper or video.
4) Prototypes ? Illustrate the visual layout of the app (what will appear on the screen, like the just in mind prototype app) ? Evaluate each prototype and motivate why you are choosing one of the prototypes. ? Draw an activity diagram to illustrate the logical flow of the app.
5) Test ? Test your app and remember that the design thinking process is linear which means that you can jump back and forth between stages at any time if you want to change or add anything.
INF Chapter 1
• Information is used for decision making • Businesses use information systems to increase revenues and reduce costs • Information systems improve the way they conduct business • Information systems impact successful personal career, organizations that reach their goals, and a society with a higher quality of life • Stakeholders must work together to build a successful information system • Information systems must be applied thoughtfully and carefully
What is information? • Information is a collection of facts • It can take many forms – text, numbers, images, audio clips and video clips are all examples • A closely related term is data, and these two terms are often used interchangeably
What is a system? • A system is a set of elements or components that interact to accomplish goals • Systems have inputs, processing mechanisms, outputs and feedback • A system processes the input to create the output. • How is a system measured: ? Efficiency is a measure of what is produced divided by what is consumed ? Effectiveness is a measure of the extent to which a system achieves its goals. ? A system performance standard is a specific objective of the system
What is an information system: • An information system (IS) is a set of interrelated components that collect, manipulate, store and disseminate information and provide a feedback mechanism to meet an objective. It is the feedback mechanism that helps organizations achieve their goals, such as increasing profits or improving customer service. • Input is the activity of gathering and capturing data. In producing • Processing means converting or transforming this input into useful outputs. Processing can involve making calculations, comparing data and taking alternative actions, and storing data for future use • Output involves producing useful information, usually in the form of documents and reports. • feedback is information from the system that is used to make changes to input or processing activities. • proactive – predicting future events to avoid problems. This concept, often called forecasting, can be used to estimate future sales and order more inventory before a shortage occurs
Characteristics of valuable information: • Accessible- Information should be easily accessible by authorized users so they can obtain it in the right format and at the right time to meet their needs • Accurate- Accurate information is error free. In some cases, inaccurate information is generated because inaccurate data is fed into the transformation process • Complete- Complete information contains all the important facts, but not more facts than are necessary (see the Simple characteristic below) • Economical- Information should also be relatively economical to produce. Decision makers must always balance the value of information with the cost of producing it
• Flexible- Flexible information can be used for a variety of purposes. For example, information on how much inventory is on hand for a particular part can be used by a sales representative in closing a sale, by a production
manager to determine whether more inventory is needed, and by a financial executive to determine the total value the company has invested in inventory • Relevant – Relevant information is important to the decision maker • Reliable – Reliable information can be depended on. In many cases, the reliability of the information depends on the reliability of the data-collection method. In other instances, reliability depends on the source of the information. A rumour from an unknown source that oil prices might go up may soon not be reliable (even though it might be useful) • Secure- Information should be secure from access by unauthorized users • Simple- Information should be simple, not overly complex. Sophisticated and detailed information might not be needed. In fact, too much information can cause information overload, whereby a decision maker has too much information and is unable to determine what is really important • Timely- Timely information is delivered when it is needed. Knowing last week’s weather conditions will not help when trying to decide what coat to wear today • Verifiable- Information should be verifiable. This means that you can check it to make sure it is correct, perhaps by checking many sources for the same information
Manual and computer based information systems: • An information system can be manual, for example paper-based, or computerized • A computer-based information system (CBIS) is a single set of hardware, software, databases, telecommunications, people, and procedures that are configured to collect, manipulate, store, and process data into information
Components of CBIS: 1. Hardware consists of computer equipment used to perform input, processing and output activities 2. Software consists of the computer programs that govern the operation of the computer. These programs allow a computer to process payroll, send bills to customers and provide managers with information to increase profits, reduce costs and provide better customer service. 3. A database is an organized collection of facts and information, typically consisting of two or more related data files 4. Telecommunications is the electronic transmission of signals for communications, which enables organizations to carry out their processes and tasks through computer networks. 5. Networks connect computers and equipment in a building, around the country or around the world to enable electronic communication. 6. The Internet is the world’s largest computer network, actually consisting of thousands of interconnected networks, all freely exchanging information
The internet has lead to: ? cloud computing, where software and data storage are provided as an Internet service and are accessed via a web browser. ? The technology used to create the Internet is also being applied within companies and organizations to create intranets, which allow people within an organization to exchange information and work on projects. ? n extranet is a network based on web technologies that allows selected outsiders, such as business partners and customers, to access authorized resources of a company’s intranet. 7. People are the most important element in most computer-based information systems. The people involved include users of the system and information systems personnel, including all the people who manage, run, program and maintain the system. 8. Procedures include the strategies, policies, methods and rules for using the CBIS, including the operation, maintenance and security of the computer.
Business information systems • The most common types of information systems used in business organizations are those designed for electronic and mobile commerce, transaction processing, management information and decision support
• A transaction is any business-related exchange, such as payments to employees, sales to customers or payments to suppliers • A transaction processing system (TPS) is an organized collection of people, procedures, software, databases and devices used to record completed business transactions. If you understand a transaction processing system, you understand basic business operations and functions. • Enterprise systems help organizations perform an integrate important tasks. • Enterprise Resource Planning ? An enterprise resource planning (ERP) system is a set of integrated programs that manages the vital business operations for an entire multisite, global organization. An ERP system can replace many applications with one unified set of programs, making the system easier to use and more effective- Supports Manufacturing and finance. • E-commerce involves any business transaction executed electronically between companies (business-tobusiness, ‘B2B’), companies and consumers (business-to-consumer, ‘B2C’), consumers and other consumers (consumer-to-consumer, ‘C2C’), business and the public sector, and consumers and the public sector • Mobile commerce (m-commerce) refers to transactions conducted anywhere, anytime. • Electronic business (e-business) goes beyond e-commerce and e-procurement by using information systems and the Internet to perform all business-related tasks and functions, such as accounting, finance, marketing, manufacturing and human resource activities • A management information system (MIS) is an organized collection of people, procedures, software, databases and devices that provides routine information to managers and decision makers. An MIS focuses on operational efficiency • A decision support system (DSS) is an organized collection of people, procedures, software, databases and devices that support problem-specific decision making. The focus of a DSS is on making effective decisions. Whereas an MIS helps an organization ‘do things right’, a DSS helps a manager ‘do the right thing’.
Specialized Business Information systems: • Knowledge management systems (KMS): an organized collection of people, procedures, software, databases, and devices to create, store, share, and use the organization’s knowledge and experience • Artificial Intelligence: attempts to have the computer system take on the characteristics of human intelligence. Applications include robotics and natural language processing
• Expert systems give the computer the ability to make suggestions and act like an expert in a particular field. It can help the novice user perform at the level of an expert. • Virtual reality: simulation of a real or imagined environment that can be experienced visually in three dimensions
Systems Development: • Systems development is the activity of creating or modifying business systems. • Systems development projects can range from small to very large in fields as diverse as stock analysis and video game development
• Systems Investigation and Analysis- The goal of the systems investigation is to gain a clear understanding of the problem to be solved or opportunity to be addressed. • Systems Design, Implementation, and Maintenance and Review ? Systems design determines how the new system will work to meet the business needs defined during systems analysis. ? Systems implementation involves creating or acquiring the various system components (hardware, software, databases, etc.) defined in the design step, assembling them and putting the new system into operation. ? The purpose of systems maintenance and review is to check and modify the system so that it continues to meet changing business needs.
Information systems in Society, Business and Industry:
Security, Privacy and Ethical Issues in Information Systems and the Internet • Increasingly, the ethical use of systems has been highlighted in the news. Ethical issues concern what is generally considered right or wrong. Some IS professionals believe that computers may create new opportunities for unethical behaviour. • To protect against these threats, you can install security and control measures
Computer and Information Systems Literacy • In the twenty-first century, business survival and prosperity have continued to become more difficult • Computer literacy is a knowledge of computer systems and equipment and the ways they function. It stresses equipment and devices (hardware), programs and instructions (software), databases and telecommunications. • Information systems literacy is the knowledge of how data and information are used by individuals, groups and organizations. It includes knowledge of computer technology and the broader range of information systems. Most important, it encompasses how and why this technology is applied in business. • Information Systems in the Functional Areas of Business- Information systems are used in all functional areas and operating divisions of business • Information Systems in Industry- In addition to being used in every department in a company, information systems are used in almost every industry or field in business
Global Challenges in IS • Cultural challenges • Language challenges • Time and distance challenges • Infrastructure challenges • Currency challenges • Product and service challenges • Technology transfer issues • National laws • Trade agreements
Summary: • Information: collection of facts organized in such a way that they have value beyond the facts themselves • System: a set of elements that interact to accomplish a goal • Components of an information system: input, processing, output, and feedback • Computer-based information system (CBIS): a single set of hardware, software, databases, telecommunications, people, and procedures that are configured to collect, manipulate, store, and process data into information • Transaction processing system (TPS): an organized collection of people, procedures, software, databases, and devices used to record completed business transactions • Management information system (MIS): an organized collection of people, procedures, software, databases, and devices that provides routine information to managers and decision makers • Decision support system (DSS): an organized collection of people, procedures, software, databases, and devices used to support problem-specific decision making
INF Chapter 2- Information Systems in Organisations
2.1 Introduction to Organisations • An organization is a formal collection of people and other resources established to accomplish a set of goals. • Primary goal of a for-profit organization – to maximize shareholder value, often measured by the price of the company stock • An organization is a system, which has inputs, processing mechanisms, outputs and feedback. • Subsystems contain processes that help turn inputs into goods or services of increasing value • Value chain-A series (chain) of activities that includes inbound logistics, warehouse and storage, production, finished product storage, outbound logistics, marketing and sales, and customer service. • Supply chain management (SCM) and customer relationship management (CRM) are two key parts of managing the value chain • SCM- determine what supplies, what quantities, and how supplies should be processed, monitored and controlled. • CRM- all aspects of customer encounters like marketing and advertising; helps a company collect data on customers, through IS software (loyalty cards) • Role of IS: Traditional view- organizations use them to control and monitor processes and ensure effectiveness and efficiency. Contemporary view- information systems are often so intimately involved that they are part of the process itself.
Organisational Structures • Organizational structure- Organizational subunits and the way they relate to the overall organization. • Traditional organizational structure- similar to a managerial pyramid- the hierarchy of decision making and authority flows from strategic management at the top down to operational management and non-management employees. Also called a hierarchical structure. • Flat organizational structure- A structure with a reduced number of management layers, giving more empowerment • Empowerment- Giving employees and their managers more responsibility and the authority to make decisions, take certain actions and have more control over their jobs. • Project organizational structure-A structure centred on major products or services. • Team organizational structure-A structure centred on work teams or groups. • Virtual organizational structure- employs individuals, groups or complete business units in geographically dispersed areas that can last for a few weeks or years, often requiring telecommunications or the Internet- can reduce costs, and provide a extra level of security.
Organizational Change • Organizational change-The responses that are necessary so that for-profit and non-profit organizations can plan for, implement and handle change. • Can be caused by internal and external factors, and can be sustaining (positive) or disruptive • A new IS will cause change ? When a company introduces a new information system, a few members of the organization must become agents of change –champions of the new system and its benefits ? Understanding the dynamics of change can help them confront and overcome resistance so that the new system can be used to maximum efficiency and effectiveness
Strategies to contain costs • Outsourcing-Contracting with outside professional services to meet specific business needs, often to trim expenses or benefit from the expertise of a service provider • On-demand computing-Contracting for computer resources to rapidly respond to an organization’s varying workflow. Also called ‘on-demand business’ and ‘utility computing’. • Downsizing-Reducing the number of employees to cut cost • Organizational learning-The adaptations to new conditions or alterations of organizational practices over time.
Reengineering and Continuous Improvement • To stay competitive, organizations must occasionally change the activities, tasks, or processes they use to achieve their goals • Reengineering-Also known as ‘process redesign’ and ‘business process reengineering’ (BPR). The radical redesign of business processes, organizational structures, information systems and values of the organization to achieve a breakthrough in business results. • Reengineering can reduce delivery times, increase product and service quality, enhance customer satisfaction, and increase revenues and profitability • Continuous improvement-Constantly seeking ways to improve business processes to add value to products and services- this continual change will increase customer satisfaction and loyalty and ensure long-term profitability.
User Satisfaction and Technology Acceptance • To be effective, reengineering and continuous improvement efforts must result in satisfied users and be accepted and used throughout the organization. You can determine the actual usage of an information system by the amount of technology diffusion and infusion. • Technology diffusion- A measure of how widely technology is spread throughout the organization. • Technology infusion-The extent to which technology is deeply integrated and embedded into an area or department. • An organization might have a high level of diffusion and infusion, but this does not necessarily mean that information systems are being used to their full potential
The Applications Portfolio • Applications portfolio-A scheme for classifying information systems according to the contribution they make to the organization. 1. Support applications- make work more convenient but are not essential, like instant messaging software. 2. Key operational applications-They are essential. Without them the organization could not conduct business, like transaction processing systems 3. Strategic application- gives a firm a competitive advantage. 4. Future strategic application- ideas for systems which, if fully developed and deployed, might one day become strategic applications, aka ‘potential strategic’ or ‘high potential’ application
Success Factors • It is of vital importance that a company’s information systems are aligned with the company’s goals • The main way of achieving alignment is for senior managers to consider the business processes they have in place to achieve company goals, and ask, what information systems are needed to support these business processes • Alignment-When the output from an information system is exactly what is needed to help a company achieve its strategic goals, the two are said to be in alignment. • Less frequently a business, typically a small business or even a single entrepreneur, will consider what technology is available to them and ask, what business goals can be achieved with it • Other success factors include: ? Senior management must be committed to development and purchase of IS ? End-users of the system should be involved in the development ? Time must be taken to carefully determine requirements and practice requirement engineering ? Strong project management in the development and purchase of IS
2.2 Competitive Advantage • Competitive advantage-The ability of a firm to outperform its industry; that is, to earn a higher rate of profit than the industry norm. • It can result from higher-quality products, better customer service, and lower costs • Often, a competitive advantage will depend on a carefully designed information system
Factors That Lead Firms to Seek Competitive Advantage • Porter’s 5 forces model- identify role that IS has on each 1. the rivalry among existing competitor 2. the threat of new entrants 3. the threat of substitute products and services 4. the bargaining power of buyers 5. the bargaining power of supplier
Strategies to attain competitive advantage • Cost Leadership- having the lowest cost of operation in the industry • Differentiation- to deliver different cost of productions and services, producing a variety • Niche strategy- deliver only to a small market, high quality
• Altering the Industry Structure- making conditions more favourable, creating strategic alliances • Creating New Products and Services- can stagnate if otherwise • Improving Existing Product Lines and Service- sometimes only minor changes needed
2.3 Evaluating IS • Once an information system has been implemented, management will want to assess how successful it has been in achieving its goals.
Approaches to evaluating IS • Productivity- A measure of the output achieved divided by the input required. Productivity = (Output/Input) × 100%. • Return on Investment (ROI)- investigates the additional profits or benefits that are generated as a percentage of the investment in IS technology. • Earnings Growth- The increase in profit • Market Share- the percentage of sales that a product or service has in relation to the total market. • Customer Awareness and Satisfaction- determine whether IS has increased this • Total Cost of Ownership (TCO)- measurement of the total cost of owning computer equipment, including desktop computers, networks and large computers. • Risk- of designing, developing and implementing these systems.
2.4 Careers in Information Systems • Operations- work with information systems in corporate or business unit computer facilities, focused on efficiency rather than effectiveness; e.g. systems- or data-entry operators • Systems Development- focuses on specific development projects and ongoing maintenance and review, e.g. system analysts who determine what outputs are needed, and then make sure the appropriate outputs are purchased • Support- provides user assistance in hardware and software acquisition and use, data administration, user training and assistance, and web administration. • Information Service Units- basically a miniature IS department attached and directly reporting to a functional area in a large organization
Typical IS Titles and Functions • The Chief Information Officer (CIO)- A senior manager who employs an IS department’s equipment and personnel to help the organization attain its goals; needs technical and business skills • LAN Administrator ? Local area network (LAN)- A computer network that connects computer systems and devices within a small area, such as an office, home or several floors in a building. ? administrators set up and manage the network hardware, software and security processes, and they isolate and fix operational problems • Internet Careers- web operations, web development and web administration. • Systems Developers- design and write software; typically graduates with degrees in technical subjects such as computer science, mathematics or engineering. • Other IS Careers- Technical writing and interface design, and they often have certification.
INF Chapter 3: Hardware: Input, Processing, Output and Storage Devices
Principles • Assembling an effective, efficient set of computer hardware devices requires understanding their role in supporting the underlying information systems and the needs of the organization. The computer hardware objectives are subordinate to, but supportive of, the information systems and the needs of the organization • When selecting computer hardware, you must consider the current and future needs of the information systems and the organization. Your choice of a hardware device should always allow for later improvements to meet evolving organizational needs
Hardware Components for Processing • Each computer processes its input through one or more central processing units and primary storage • Hardware: machinery that assists in the input, processing, storage, and output activities of an information system • Hardware components: central processing unit (CPU), input and output devices, communications devices, primary storage devices, and secondary storage devices • CPU (Central processing unit): Consists of three elements: 1. The arithmetic/logic unit (ALU) performs mathematical calculations and makes logical comparisons 2. The control unit sequentially accesses program instructions, decodes them, and coordinates the flow of data in and out of the ALU, registers, primary and secondary storage, and various output devices 3. Registers are high-speed storage areas used to temporarily hold small units of program instructions and data immediately before, during, and after execution by the CPU
Hardware Components in Action- Processing characteristics and Functions • Instruction time (i-time) The time it takes to perform the fetch instruction and decode instruction steps of the instruction phase. • Execution time (e-time) The time it takes to execute an instruction and store the results. • Machine Cycle Time- The time in which a machine cycle occurs is measured in nanoseconds (one-billionth of one second) and picoseconds (one-trillionth of one second). ? Measured in MIPS (Millions of instructions per second, a measure of machine cycle time.) • Clock speed-A series of electronic pulses produced at a predetermined rate that affects machine cycle time. • Physical Characteristics of the CPU- Most CPUs are collections of digital circuits imprinted on silicon wafers or chips, each no bigger than the tip of a pencil eraser. • Moore’s Law-A hypothesis stating that transistor densities on a single chip will double every two years
Storage • Primary storage or main memory ? provides the CPU with a working storage area for program instructions and data ? The chief feature of main memory is that it rapidly provides the data and instructions to the CPU • Secondary storage, also called permanent storage, ? allows organizations to store large amounts of data and instructions more permanently than main memory allows ? Compared with main memory, secondary storage offers the advantages of non-volatility, greater capacity, and greater economy • Storage capacity in bytes (B)- Eight bits that together represent a single character of data. • Types of Memory ? random access memory (RAM) -A form of memory in which instructions or data can be temporarily stored. ? Read-only memory (ROM)- A non-volatile form of memory. ? Cache memory- A type of high-speed memory that a processor can access more rapidly than main memory. • Multiprocessing-The simultaneous execution of two or more instructions at the same time.
• Coprocessor- The part of the computer that speeds processing by executing specific types of instructions while the CPU works on another processing activity. • Parallel computing- The simultaneous execution of the same task on multiple processors to obtain results faster. ? Systems with thousands of such processors are known as massively parallel processing systems ? The most frequent uses for parallel computing include modelling, simulation and analysing large amounts of data • Grid computing- The use of a collection of computers, often owned by multiple individuals or organizations, to work in a coordinated manner to solve a common problem; a low-cost approach to parallel computing
Secondary Storage Access Methods • Sequential access (SASDs)- A retrieval method in which data must be accessed in the order in which it was stored. • Direct access (DASDs)- A retrieval method in which data can be retrieved without the need to read and discard other data.
Devices • Magnetic storage uses tape or disc devices covered with a thin magnetic coating that enables data to be stored as magnetic particles • magnetic disc A direct access storage device with bits represented by magnetized areas. • redundant array of independent/inexpensive discs (RAID)A method of storing data that generates extra bits of data from existing data, allowing the system to create a ‘reconstruction map’ so that, if a hard drive fails, the system can rebuild lost data. • Virtual tape A storage device for less frequently needed data so that it appears to be stored entirely on tape cartridges, although some parts of it might actually be located on faster hard discs. • optical storage device A form of data storage that uses lasers to read and write data. ? DVD ? CD ? Blu-Ray • Solid state storage devices (SSDs) store data in memory chips rather than magnetic or optical media. ? Universal Serial Bus (USB) flash drive – A type of SSD
Enterprise storage options • Attached storage- the devices attached to a single computer • Network-attached storage- storage devices that attach to a network instead of to a single computer • Storage area network- similar to network-attached storage, except there is a dedicated, special-purpose, highspeed network that provides direct connections between data-storage devices and computers across the enterprise • Storage as a service- A data storage model where a data storage service provider rents space to individuals and organizations.
Data: Input and Output • The transferring machine-readable data into the system • Data entry: Converting human-readable data into a machine-readable form • Input often requires transferring human-readable data, such as a sales order, into the computer system • ‘Human-readable’ means data that people can read and understand. A sheet of paper containing inventory figures is an example of human-readable data • Machine-readable data, such as a bar code, can be understood and read by computer devices • Getting data into the computer system is a two-stage process: ? human-readable data is converted into a machine-readable form through data entry ? transferring the machine-readable data into the system- This is data input
Input devices • devices that transform human-readable data to machine-readable data • Personal Computer Input Devices: A keyboard and a computer mouse are the most common devices used for entry and input of data such as characters, text and basic commands. • speech-recognition technology: Input devices that recognize human speech. • Digital cameras: An input device used with a PC to record and store images and video in digital form. • Scanning devices: capture image and character data • Optical Data Readers: You can also use a special scanning device called an optical data reader to scan documents. There are two categories of Optical Data Readers: – optical mark recognition (OMR): this reader is the one that marks our multiple choice tests – optical character recognition (OCR): this reader can transform a hard document (typed or handwritten) into an editable document on your computer • magnetic strip card: A type of card that stores a limited amount of data by modifying the magnetism of tiny iron-based particles contained in a band on the card. • Chip-and-PIN cards: A type of card that employs a computer chip that communicates with a card reader using radio frequencies; it does not need to be swiped at a terminal. • contactless card: A card with an embedded chip that only needs to be held close to a terminal to transfer its data; no PIN needs to be entered. • Point-of-sale (POS) devices: A terminal used to enter data into the computer system. • Automated Teller Machine (ATM), is a terminal that bank customers use to perform transactions with their bank accounts. • Touch-sensitive screens: you can start a program or trigger other types of action • A barcode scanner employs a laser scanner to read a barcoded label and pass the data to a computer. • Radio frequency identification (RFID): A technology that employs a microchip with an antenna to broadcast its unique identifier and location to receivers.
Output devices – • Devices that transform machine-readable data to human-readable data • plasma display: A type of display using thousands of smart cells (pixels) consisting of electrodes and neon and xenon gases that are electrically turned into plasma (electrically charged atoms and negatively charged particles) to emit light. • LCD displays: Flat display that uses liquid crystals – organic, oil-like material placed between two polarizers – to form characters and graphic images on a backlit screen. • Organic light-emitting diode (OLED): Flat display that uses a layer of organic material sandwiched between two conductors, which in turn are sandwiched between a glass top plate and a glass bottom plate so that when electric current is applied to the two conductors, a bright, electroluminescent light is produced directly from the organic material. • Printers: One of the most useful and common forms of output is called hard copy, which is simply paper output from a printer. • Plotters: are a type of hard-copy output device used for general design work. Businesses typically use plotters to generate paper or acetate blueprints, schematics and drawings of buildings or new products. • digital audio player: A device that can store, organize and play digital music files. • E-book Readers: The digital media equivalent of a conventional printed book is called an e-book
Types of Computer System (small to big) • Handheld computer – A single-user computer that provides ease of portability because of its small size. • Smart phone – A handheld computer that combines the functionality of a mobile phone, camera, web browser, email tool, MP3 player and other devices into a single device. • Portable Computers – A computer small enough to carry easily. • Thin Client – A low-cost, centrally managed computer with essential but limited capabilities and no extra drives (such as CD or DVD drives) or expansion slots.
• Desktop PC – A nonportable computer that fits on a desktop and that provides sufficient computing power, memory and storage for most business computing tasks. • Workstation – A more powerful personal computer used for mathematical computing, computer-assisted design and other high-end processing, but still small enough to fit on a desktop • Server – A computer employed by many users to perform a specific task, such as running network or Internet applications. • Mainframe Computers – A large, powerful computer often shared by hundreds of concurrent users connected to the machine over a network. • Supercomputers – The most powerful computer systems with the fastest processing speeds. Green computing • A program concerned with the efficient and environmentally responsible design, manufacture, operation and disposal of IS-related products.
Selecting ; upgrading computer systems • Hard drive considerations: capacity, speed, and media capabilities are key features. Today’s business software and large video, audio, and graphics files require lots of storage • Main memory considerations: having more RAM means you can run software faster • Printer considerations: major considerations are price, colour, and speed • Many companies now consider environmental issues, as well when selecting and upgrading
INF Chapter 4. Software: Systems and Application Software
4.1 An overview of software • Software consists of computer programs that control the workings of computer hardware. • Computer programs: Sequences of instructions for the computer • Documentation: Text that describes a program’s functions to help the user operate the computer system. • Systems software • Def: The set of programs that coordinate the activities and functions of the hardware and other programs throughout the computer system. Each type is designed for a specific CPU and class of hardware. • Computer system platform: The combination of a hardware configuration and systems software • Application software ? Programs that help users solve particular computing problems ? Application software resides on the computer’s hard drive before it is brought into the computer’s memory and run. ? Can also be stored on CDs, DVDs and USB flash drives. ? Rich internet application: a web-delivered application combines the hardware services of the web server and PC to deliver software service through a web browser interface Supporting individual, group and organisational goals • Every organisation relies on the contributions of people, groups and the entire enterprise to achieve its business objectives • A useful way to identify the scope of problems and opportunities that an organisation addresses. This scope is called the sphere of influence • Most companies’ spheres are personal, workgroup and enterprise Software Personal Workgroup Enterprise Systems software Smartphone, tablet computer, personal computer, workstation operating systems Network operating systems Server and mainframe operating systems Application software Word processing, spreadsheet, database and graphics Electronic mail, group scheduling, shared work and collaboration General ledger, order entry, payroll and human resources
• Personal sphere of influence: The sphere of influence that serves the needs of an individual user • Information systems in the personal sphere of influence improve personal effectiveness, increasing the amount and quality of work done. • Personal productivity software: The software that enables users to improve their personal effectiveness, increasing the amount of work and quality of that can be done • Workgroup: Two or more people who work together to achieve a common goal • Workgroup sphere of influence: The sphere of influence that helps workgroup members achieve their common goals • Enterprise sphere of influence: The sphere of influence that serves the needs of the firm in its interaction with its environment
4.2 Systems software • Controls the operations of the computer and is one of the most critical functions of system software. Includes operating systems, utility programs and middleware Operating system • Def: A set of computer programs that controls the computer hardware and acts as an interface with applications • OS’s can control one or more computers and allow multiple users to interact with one computer. There are various combinations of OSs, computers and users ? Single computer with single user. Personal computers, tablets or smartphones. Windows, Mac OS X, Android ? Single computer with multiple simultaneous users: typical larger server or mainframe computers that can support hundreds or thousands of users using the same computer at once. UNIX, z/OS, HP UX ? Multiple computers with multiple users: typically a network of computers such as a home network with many computers attached supporting multiple users. Sometimes located around the world. Red Hat Linux, Windows Server, Mac OS X server. ? Special-purpose computers: a number of computers with specialised functions, such as controlling military aircraft, space shuttles, digital cameras, or home appliances. Windows Embedded, Symbian, some distributions of Linux • Computers can be booted from a rescue disk (CD, DVD, USB flash drive) that contains some or all of the OS in case the primary drive malfunctions. • The set of programs that make up the OS performs various activities: ? Performs common computer hardware functions ? Provides a user interface and input/output management and a degree of hardware independence ? Manages system memory, processing tasks and files ? Sometimes provides network capability ? Controls access to system resources • Kernel: Heart of OS and controls the most critical processes. • Common hardware functions ? Get input from keyboard or other input devices ? Retrieve data from discs ? Store data on discs ? Display information on monitor or printer
User interface and input/output management • User interface: the element of the operating system that allows people to access and interact with the computer system • Command-based user interface: a user interface that requires you to give text commands to the computer to perform basic activities • Graphical user interface (GUI): an interface that displays pictures (icons) and menus that people use to send commands to the computer system Hardware independence • Application program interface: tools software developers use to build application software without needing to understand the inner workings of the OS and hardware When new hardware technologies are introduced the operating adjusts to those changes and not the application software that runs on the operating system Memory management • The OS controls how memory is accessed, maximising the use of available memory and storage to provide optimum efficiency. To increase the performance of an old computer, upgrade the OS and add memory.
Virtual memory: space on the hard disk is allocated to supplement the RAM. This works by swapping programs or parts of programs between memory and one or more drives – this is called paging. The amount of jobs that can be run in a given time span is increased Processing tasks • Task management allocates the computer resources to make the best use of each system’s assets. Certain OS supports multitasking which allows you to work in the foreground while other tasks are processed in the background • Time sharing allows more than one person to use a computer system at the same time. The ability of a computer to handle an increasing number of concurrent users is called scalability. Networking capability • Most OS include networking capabilities, so computers can join in a network to send and receive data and share resources Access to system resources and security • The OS would typically initiate a logon sequence with username and password, or control which resources a user is allowed to access. File management • The OS manages files to ensure files in secondary storage is accessible when needed and protected from unauthorised access. Current operating systems Personal Workgroup Enterprise Microsoft Windows Microsoft Windows Server Microsoft Windows Server Mac OS X, iOS Mac OS X server Linux Linux Linux UNIX Google Android, Chrome OS UNIX IBM i and z/OS HP WebOS IBM i and z/OS HP-UX HP-UX
Microsoft PC operating systems • PC-DOS and MS-DOS was developed to support the IBM PC introduced in the 1980s. Windows 10 is the current OS and supports touch displays, laptops and tablets Apple Computer operating systems • July 2001 Mac OS X was released for the Mac based on the UNIX OS. Because Macs use Intel processors, other OS such as Windows can be selected during boot and used then. Known as dual booting. Linux • Developed in 1991. Distributed under GNU General Public License and its source code is freely available to anyone. Thus, an open-source operating system. Not necessarily free, but can be modified as a user pleases. Google • Started as a search engine, developed software (Google docs), created a mobile OS (Android), web browser (Chrome) and Android has more than 100 million users currently. • Chrome OS is also developed by Google and is based on Linux for netbooks and nettops and desktop PCs primarily used to access web-based info. Workgroup operating systems • Windows server o Designed to perform tasks vital for websites and corporate web apps o E.g. to coordinate large data centres. • UNIX
o Originally developed by AT&T for minicomputers. Can be used on many computer system types and platforms including work stations, servers and mainframe computers. • Red Hat Linux o Offers a Linux network that taps into talents of tens of thousands of volunteer programmers that generate improvements for the Linux OS. • Mac OS X server o The first modern server OS from Apple Computer and is based on the UNIX OS. Enterprise operating systems • Mainframe computers (big iron) provide the computing and storage capacity to meet massive data processing requirements, providing users with high performance and excellent system availability.
Operating systems for small computers, embedded computers and special-purpose devices • Known as embedded operating systems or only embedded systems. They are usually designed to perform specialised tasks. Like a GPS unit whose OS only controls navigating • Mobile phone embedded systems and OS ? Mobile phones traditionally used embedded systems to provide communication, but evolved into fullfledged personal computer operating systems such as iOS, Android, Windows Mobile • Windows embedded ? A family of Microsoft OSs embedded into small computer devices ? Several versions to support set top boxes, media players, digital cameras, ATMs etc are available • Proprietary Linux-Based Systems ? Designed for a specific device Utility programs • Def: program that helps to perform maintenance or correct problems with a computer system • For example, some utility programs merge and sort sets of data, keep track of computer jobs being run, compress files of data before they are stored or transmitted over a network (thus saving space and time) and perform other important tasks. Hardware utilities • Hardware utilities can check the status of all parts of the PC, including hard discs, memory, modems, speakers and printers Security utilities • Antivirus and antispyware software can be installed to constantly monitor and protect the computer. If a virus or spyware is found, most of the time it can be removed. File-compression utilities • File-compression programs can reduce the amount of disc space required to store a file or reduce the time it takes to transfer a file over the Internet Spam-filtering utilities • Email software and services include spam-filtering utilities to assist users with these annoyances. Email filters identify spam by learning what the user considers spam and routing it to a junk mail folder Network and internet utilities • A broad range of network- and systems-management utility software is available to monitor hardware and network performance and trigger an alert when a server is crashing or a network problem occurs Server and mainframe utilities • Some utilities enhance the performance of servers and mainframe computers
Other utilities • Utility programs are available for almost every conceivable task or function. Managing the vast array of operating systems for smartphones and mobile devices, for example, has been difficult for many companies. Utility programs can help Middleware • Middleware is software that allows various systems to communicate and exchange data It is often developed to address situations where a company acquires different types of information systems through mergers, acquisitions or expansion and wants the systems to share data and interact
4.3 Application software • The primary function of application software is to apply the power of the computer to give people, workgroups and the entire enterprise the ability to solve problems and perform specific tasks Overview of application software Proprietary software is one-of-a-kind software designed for a specific application and owned by the company, organization or person that uses it Off-the-shelf software is mass-produced by software vendors to address needs that are common across businesses, organizations or individuals Comparison of Proprietary and Off-the-Shelf Software
• Many companies use off-the-shelf software to support business processes. • Key questions for selecting off-the-shelf software include the following. 1. First, will the software run on the OS and hardware you have selected? 2. Second, does the software meet the essential business requirements that have been defined? 3. Third, is the software manufacturer financially solvent and reliable? 4. Finally, does the total cost of purchasing, installing and maintaining the software compare favourably to the expected business benefits? • Another approach to obtaining a customized software package is to use an application service provider. An application service provider (ASP) is a company that can provide the software, support and computer hardware on which to run the software from the user’s facilities over a network • Today, many companies are running software on the web. This approach is called Software as a Service (SaaS), which allows businesses to subscribe to web-delivered application software. In most cases, the company pays a monthly service charge or a per-use fee • Cloud computing refers to the use of computing resources, including software and data storage, on the Internet (the cloud) rather than on local computers Cloud computing also provides the benefit of being able to easily collaborate with others by sharing documents on the Internet. • ASP, SaaS and cloud computing, however, involve some risks. For example, sensitive information could be compromised in a number of ways, including unauthorized access by employees or computer hackers; the host might not be able to keep its computers and network up and running as consistently as necessary; or a disaster could disable the host’s data centre, temporarily putting an organization out of business
Personal application software Word processing • Word-processing applications are installed on most PCs today. These applications come with a vast array of features, including those for checking spelling, creating tables, inserting formulas, creating graphics and much more Spreadsheet analysis • Spreadsheets are powerful tools for manipulating and analysing numbers and alphanumeric data • Features of spreadsheets include formulas, statistical analysis, built-in business functions, graphics, limited database capabilities and much more Database applications • Database applications are ideal for storing, organizing and retrieving data. Database manipulations include merging, editing and sorting data Presentation graphics program • Presentation graphics programs can be used to develop advertising brochures, announcements and full-colour presentations, and to organize and edit photographic images Personal information managers • Personal information management (PIM) software helps people, groups and organizations store useful information, such as a list of tasks to complete or a set of names and addresses. PIM software usually provides an appointment calendar, an address book or contacts list, and a place to take notes Software suites and integrated software packages • A software suite is a collection of single programs packaged together in a bundle. Software suites can include a word-processor, spreadsheet program, database management system, graphics program, communications tools, organizers and more. Some suites support the development of web pages, note taking and speech recognition so that applications in the suite can accept voice commands and record dictation
• In addition to suites, some companies produce integrated application packages that contain several programs.
• For example, Microsoft Works is one program that contains a basic word processor, spreadsheet, database, address book, calendar and other applications. Although not as powerful as stand-alone software included in software suites, integrated software packages offer a range of capabilities for less money • Other personal application software-Tax prep programs, web sites, music composing, media editing. Game playing
Mobile application software———————
Workgroup application software • Workgroup application software is designed to support teamwork, whether team members are in the same location or dispersed around the world. This support can be accomplished with software known as groupware that helps groups of people work together effectively. Enterprise application software • Software that benefits an entire organization – enterprise application software – can also be developed specifically for the business or purchased off the shelf. Enterprise software also helps managers and workers stay connected.
Application Software for Information, Decision Support and Competitive Advantage Specialized application software for information, decision support and competitive advantage is available in every industry. For example, many schools and colleges use Blackboard or other learning management software to organize class materials and grades
4.4 Programming languages • Both system and application software are written in coding schemes called programming languages. The primary function of a programming language is to provide instructions to the computer system so that it can perform a processing activity • Information systems professionals work with programming languages, which are sets of keywords, symbols and rules for constructing statements that people can use to communicate instructions to a computer • Each language also has its own set of rules, called the syntax (a set of rules associated with a programming language) of the language. The language syntax dictates how the symbols, keywords and commands should be combined into statements capable of conveying meaningful instructions to the CPU
The evolution of programming languages
oriented and artificial intelligence languages • In general, these languages are easier for nonprogrammers to use, compared with older generation languages. • Visual programming uses a graphical or ‘visual’ interface combined with text-based commands. Prior to visual programming, programmers were required to describe the windows, buttons, text boxes and menus that they were creating for an application by using only text-based programming language commands • Programming languages used to create artificial intelligence or expert systems applications are often called fifth-generation languages (5GLs). Fifth-generation languages are sometimes called natural languages because they use even more English-like syntax than 4GLs. They allow programmers to communicate with the computer by using normal sentences. For example, computers programmed in fifth-generation languages can understand queries such as ‘How many athletic shoes did our company sell last month?’ • With third-generation and higher-level programming languages, each statement in the language translates into several instructions in machine language. A special software program called a compiler converts the programmer’s source code into the machine-language instructions, which consist of binary digits. A compiler creates a two-stage process for program execution. First, the compiler translates the program into a machine language; second, the CPU executes that program. Another approach is to use an interpreter, which is a language translator that carries out the operations called for by the source code. An interpreter does not produce a complete machinelanguage program. After the statement executes, the machine-language statement is discarded, the process continues for the next statement and so on.
4.5 Software Issues and Trends Because software is such an important part of today’s computer systems, issues such as software bugs, licensing, upgrades, global software support and taxation have received increased attention. Software bug A software bug is a defect in a computer program that keeps it from performing as it is designed to perform. How to reduce: • Register all software so that you receive bug alerts, fixes and patches. • Check the manual or read-me files for solutions to known problems. • Access the support area of the manufacturer’s website for patches. • Install the latest software updates. • Before reporting a bug, make sure that you can recreate the circumstances under which it occurs. • After you can recreate the bug, call the manufacturer’s tech support line. • Consider waiting before buying the latest release of software, to give the vendor a chance to discover and remove bugs. Many schools and businesses don’t purchase software until the first major revision with patches is released.
Copyrights and licenses • Most companies aggressively guard and protect the source code of their software from competitors, lawsuits and other predators. As a result, most software products are protected by law using copyright or licensing provisions. • Those provisions can vary, however. In some cases, you are given unlimited use of software on one or two computers. • When people purchase software, they don’t actually own the software, but rather they are licensed to use the software on a computer. This is called a single-user licence. A single-user licence permits you to install the software on one or more computers, used by one person. A single-user licence does not allow you to copy and share the software with others.
Freeware and open-source software • Some software developers are not as interested in profiting from their intellectual property as others and have developed alternative copyrights and licensing agreements. Freeware is software that is made available to the public for free. Software developers might give away their product for several reasons. Some want to build customer interest and name recognition. Others simply don’t need the money and want to make a valuable donation to society.
• Freeware differs slightly from free software. Freeware simply implies that the software is distributed for free. • Open-source software is distributed, typically for free, with the source code also available so that it can be studied, changed and improved by its users.
• Much of the popular free software in use today is protected by the GNU General Public Licence (GPL). The GPL grants you the right to do the following: ? Run the program for any purpose. ? Study how the program works and adapt it to your needs. ? Redistribute copies so you can help others. ? Improve the program and release improvements to the public.
• Software under the GPL is typically protected by a ‘copyleft’ (a play on the word copyright), which requires that any copies of the work retain the same licence. A copyleft work cannot be owned by any one person, and no one is allowed to profit from its distribution. • Many believe that open-source software is often more reliable and secure than commercial software. How can this be? 1. First, because a program’s source code is readily available, users can fix any problems they discover. A fix is often available within hours of the problem’s discovery. 2. Second, because the source code for a program is accessible to thousands of people, the chances of a bug being discovered and fixed before it does any damage are much greater than with traditional software packages.
• Disadvantages? 1. The up-front costs are only a small piece of the total cost of ownership that accrues over the years that the system is in place. 2. Some claim that open-source systems contain many hidden costs, particularly for user support or solving problems with the software. Licensed software comes with guarantees and support services, while open-source software does not. Software upgrades • Software companies revise their programs periodically. • Software upgrades vary widely in the benefits that they provide, and what some people call a benefit others might call a drawback. • Deciding whether to upgrade to a new version of software can be a challenge for corporations and people with a large investment in software. Should the newest version be purchased when it is released? Some users do not always get the most current software upgrades or versions unless it includes significant improvements or capabilities. • Supporting local operations is one of the biggest challenges IS teams face when putting together standardized companywide systems. One approach that has been gaining acceptance in North America is to outsource global support to one or more third-party distributors The supplier acts as a middleman between software vendor and user, often providing distribution, support and invoicing.
INF Chapter 5- Organising and storing data
5.1 Data Management and Data Modelling • The most common type of database is a relational database, so-named because the basic structure for storing data is a table, and the word relation is another name for a table. • A relational database is defined as a series of related tables, stored together with a minimum of duplication to achieve a consistent and controlled pool of data. • The rows in a table collect together all the data about one specific entity. For example, in the customer table, each row stores all the data about one customer – Jane Smith, for instance, or Desmond Paton. These rows are known as records. • The columns in a table are the specific items of data that get stored; for example, first name, surname or telephone number. These columns are known as fields or attributes. • a primary key is used to identify individual records, and to create relationships between tables, something we will examine next.
The database approach • After a database has been set up and loaded with data, it can produce any desired reports, documents • These outputs usually appear in screen displays or hard-copy printouts
The Advantages and Disadvantages of using a Relational Database to Store data (not essential) Advantages Explanation Improved strategic use of corporate data Accurate, complete, up-to-date data can be made available to decision makers where, when and in the form they need it. The database approach can also give greater visibility to the organization’s data resource Reduced data redundancy Data is organized by the database management system (DBMS) and stored in only one location. This results in more efficient use of system storage space Improved data integrity With the traditional approach, some changes to data were not reflected in all copies of the data kept in separate files. This is prevented with the database approach because no separate files contain copies of the same piece of data Easier modification and updating The DBMS coordinates updates and data modifications. Users do not have to know where the data is physically store, as the data is stored in only one location in most cases Data and program independence The DBMS organizes the data independently of the application program, so the application program is not affected by the location or type of data. Introduction of new data types not relevant to a application does not require rewriting that application to maintain compatibility with the data file Better access to data and information Most DBMSs have software that makes it easy to access and retrieve data from a database. In most cases, users give simple commands to get important information. Relationships between records can be more easily investigated and exploited, and applications can be more easily combined Standardization of data access A standardized, uniform approach to database access means that all application programs use the same overall procedures to retrieve data and information A framework for program development Standardized database access procedures can mean more standardization of program development. Because programs go through the DBMS to gain access to data in the database, standardized database access can provide a consistent framework for program development. In addition, each application program needs to address only the DBMS, not the actual data files, reducing application development time Better overall protection of the data Accessing and using centrally located data is easier to monitor and control. Security codes and passwords can ensure that only authorized people have access to particular data and information in the database, thus ensuring privacy Shared data and information resources The cost of hardware, software and personnel can be spread over many applications and users. This is a primary feature of a DBMS
Customer table example
Disadvantages Explanation More complexity DBMS can be difficult to set up and operate. Many decisions must be made correctly for the DBMS to work effectively. In addition, users have to learn new procedures to take full advantage of a DBMS More difficult to recover from a failure With the traditional approach to file management, a failure of a file affects only a single program. With a DBMS, a failure can shut down the entire database More expensive DBMS can be more expensive to purchase and operate. The expense includes the cost of the database and specialized personnel, such as a database administrator, who is needed to design and operate the database. Additional hardware might also be required
Relationships between tables • The customer number in the order table is known as a foreign key. • An important concept when setting up relationships is ‘referential integrity’. What this means is that you cannot have an instance of a foreign key before it exists as an instance of a primary key. • if the database has enforced referential integrity (which it should) it means you can’t have an order for Customer_Number 15 unless there actually is a customer with Customer_Number 15 in the customer table. • This is an extremely convenient and useful way of organizing data (refer back to Table 5.1). It means, in this case, that the delivery address doesn’t have to be stored twice – once with the order and again with the customer details • Storing the same information twice is very bad practice and leads to all sorts of problems • A large part of organizing data involves deciding which fields are going to be primary keys and identifying where the foreign keys should be
Designing relational databases • Four stages: 1. Identify all entities. 2. Identify all relationships between entities. 3. Identify all attributes. 4. Resolve all relationships. 1. Identify entities ? This is usually done by interviewing the firm’s managers and staff ? If there are too many of them to interview, sometimes database designers will use a questionnaire to get opinions from as many people as possible. 2. Identify relationships ? You next need to identify any relationships that exist between entities. ? The sort of relationships that you have to identify are relationships that the firm wants to store information about. ? The relationship between customers and orders is definitely something that the firm will want to store, so that they can see which customers have placed which orders ? Once a relationship is identified there are three things you need to document about it: a) The degree of a relationship is simply how many entities are involved, and this figure is often two. When the degree is two, it is known as a ‘binary relationship’. b) The cardinality of a relationship is whether each entity in the relationship is related to one or more than one of the other entities. c) Last, the optionality documents whether the relationship must exist for each entity or whether it is optional. For instance, an order must be placed by a customer – there is no option. An order can’t exist unless a customer has placed it! However, a customer can be in the database even though they have no current orders, so the relationship is optional for the customer.
Order table example
? It is important to note that the database designer doesn’t get to make up the degree, cardinality and optionality herself. These are dictated to her by what are known as the enterprise rules, which the designer must uncover by, usually, interviewing staff. ? An example of the enterprise rules describing the customer-order relationship as follows ? Each order must be placed by one and only one customer ? Each customer can place many orders, but some won’t have placed any orders
3. Identify attributes ? The third stage is to identify all the attributes that are going to be stored for each entity. ? An attribute should be the smallest sensible piece of data that is to be stored. ? For example, customer name is probably a bad attribute – customer first name and surname would be better
4. Resolve relationships ? The customer–order relationship was implemented by taking the primary key of customer and posting it as a foreign key in the order table. ? This is essentially what resolving a relationship means – deciding how to implement it.
The Six Types of Binary Relationships (Not explicitly mentioned in slides) 1. One-to-one relationship, obligatory on both sides. ? E.g. Employee – Passport ? Each employee must have one and only one passport; each passport must have one and only one employee. ? To resolve this relationship, combine both entities into one table. 2. One-to-one relationship, optional on one side. ? E.g. Employee – Company car ? Each employee might have one and only one company car; each company car is owned by one and only one employee. ? To resolve this relationship, take the primary key from employee and post it as a foreign key in company car. 3. One-to-one relationship, optional on both sides. ? E.g. Employee – Laptop ? Each employee might have one laptop; each laptop might belong to one employee (but some are for general use and therefore won’t belong to anyone). ? To resolve this relationship, implement three tables – an employee table, a laptop table and a new table that we will call ‘owns’. The owns table only has two fields – employee number and laptop number. The primary key of owns is a ‘composite key’, i.e. it is the employee number and laptop number combined, and each combination of the two is unique. 4. One-to-many relationship, many side obligatory to one side. ? E.g. Customer – Order ? A customer can place many orders; but might have placed no orders, each order must be placed by one and only one employee. ? Resolve this relationship by taking the primary key from customer and posting it as a foreign key in order.
5. One-to-many relationship, many side optional to one side. ? E.g. Student – Elective module ? A student might take one elective module; each module is taken by many students (i.e. the students don’t have to take an elective module). ? Most companies would implement this in the same way as for Relationship 4 above. However, the way to avoid nulls in the foreign key is to implement three tables – one for student, one for elective module and one that we’ll call ‘studies’ (as a student studies a module). The studies table has just two fields – student number and module number. The primary key of the studies table is student number (or you could implement a composite key).
6. Many-to-many relationship. ? Student – Tutor ? Each tutor teaches many students; each student is taught by many tutors. ? To resolve this relationship, implement three tables – one for student, one for tutor, and a third we’ll call ‘teaches’. The teaches table has two fields – student number and tutor number, and its primary key is a composite key, i.e. a combination of student number and tutor number.
5.2 Database management systems (DBMS) Creating and modifying the database • Schemas or designs are entered into the DBMS (usually by database personnel) via a data definition language. • A data definition language (DDL) is a collection of instructions and commands used to define and describe data and relationships in a specific database. • A DDL allows the database’s creator to describe the data and relationships. Structured Query Language (SQL) is a DDL. • A data dictionary helps achieve the advantages of the database approach in these ways: a) Reduced data redundancy: By providing standard definitions of all data, it is less likely that the same data item will be stored in different places under different names b) Increased data reliability: A data dictionary and the database approach reduce the chance that data will be destroyed or lost. In addition, it is more difficult for unauthorized people to gain access to sensitive data and information. c) Assists program development: With a data dictionary, programmers know what data is stored and what data type each field is d) Easier modification of data and information: The data dictionary and the database approach make modifications to data easier because users do not need to know where the data is stored.
Storing and retrieving data • One function of a DBMS is to be an interface between an application program and the database. • When an application program needs data, it requests that data through the DBMS • Concurrency control: A method of dealing with a situation in which two or more people need to access the same record in a database at the same time.
Manipulating data and generating reports • After a DBMS has been installed, employees, managers and consumers can use it to review reports and obtain important information • Data manipulation language (DML): The commands that are used to manipulate the data in a database.
Logical and physical access paths
Database administration • Database administrator (DBA): The role of the database administrator is to plan, design, create, operate, secure, monitor and maintain databases. • Data administrator: A non-technical position responsible for defining and implementing consistent principles for a variety of data issues.
Selecting a database management system • The DBA often selects the DBMS for an organization. • Important characteristics of databases: ? Database size: The number of records or files in the database. ? Database cost: The purchase or lease costs of the database. ? Concurrent users: The purchase or lease costs of the database. ? Performance: How fast the database can update records. ? Integration: The ability to be integrated with other applications and databases. ? Vendor: The reputation and financial stability of the database vendor.
Using databases with other software • DBMSs are often used with other software packages or the Internet. A DBMS can act as a front-end application or a back-end application. • A back-end application interacts with other programs or applications; it only indirectly interacts with people or users
5.3 Database applications • Database applications manipulate the content of a database to produce useful information. Common manipulations are searching, filtering, synthesizing and assimilating the data contained in a database
Linking databases to the internet • Linking databases to the Internet is an incredibly useful application for organizations and individuals. Every e-commerce website uses database technology to dynamically create its web pages, saving vast amounts of efforts. • Semantic Web ? Developing a seamless integration of traditional databases with the Internet ? Allows people to access and manipulate a number of traditional databases at the same time through the Internet
Big data applications • Much of the data that organizations store comes from their Transaction Processing Systems • firms are frequently storing less well-structured data too, such as photos, videos, data from customers’ blogs, data from social networks and from their own website, including the order in which people view their web pages. All of this is often called Big Data • Big data: large amounts of unstructured data that are difficult or impossible to capture and analyse using traditional DBMSs • Big Data can provide valuable insights to help organizations achieve their goals. It can reveal which potential customers are most likely to purchase which products. It can identify where and when a customer tends to shop. It can even determine how much a customer would be willing to pay for a product. • Apache Hadoop is an open-source database that can be used to manage large unstructured datasets (Big Data)
Data warehouses • Data warehouse: A database or collection of databases that collects business information from many sources in the enterprise, covering all aspects of the company’s processes, products and customers. • Data warehouses typically start out as very large databases, containing millions and even hundreds of millions of data records. As this data is collected from various sources, one data warehouse is built that business analysts can use • To keep it accurate, the data warehouse receives regular updates. • Old data that is no longer needed is purged
Data mining • Data mining is the process of analysing data to try to discover patterns and relationships within the data. • Typically, a data warehouse is mined. Like gold mining, data mining sifts through mountains of data to find a few nuggets of valuable information • Data mining is used extensively in marketing to improve customer retention; identify cross-selling opportunities; manage marketing campaigns; market, channel and pricing analysis; and customer segmentation analysis (especially one-to-one marketing) •
Common Data Mining Applications Application Description Branding and positioning of products and services Enable the strategist to visualize the different positions of competitors in a given market using performance (or other) data on dozens of key features of the product and then to condense all that data into a perceptual map of only two or three dimensions Customer churn Predict current customers who are likely to switch to a competitor
Direct marketing Identify prospects most likely to respond to a direct marketing campaign (such as a direct mailing) Fraud detection Highlight transactions most likely to be deceptive or illegal Market basket analysis Identify products and services that are most commonly purchased at the same time (e.g. nail polish and lipstick) Market segmentation Group customers based on who they are or what they prefer
Trend analysis Analyse how key variables (e.g. sales, spending, promotions) vary over time Business intelligence • Business intelligence (BI) involves gathering enough of the right information in a timely manner and usable form, and analysing it so that it can be used to have a positive effect on business strategy, tactics or operations • Competitive intelligence is one aspect of BI and is limited to information about competitors and the ways that knowledge affects strategy, tactics and operations. ? Competitive intelligence is a critical part of a company’s ability to see and respond quickly and appropriately to the changing marketplace • Counter intelligence describes the steps an organization takes to protect information sought by ‘hostile’ intelligence gatherers ? One of the most effective counterintelligence measures is to define ‘trade secret’ information relevant to the company and control its dissemination.
Elements of a data warehouse
Distributed databases • A distributed database – a database in which the data is spread across several smaller databases connected through telecommunications devices • Distributed databases give organizations more flexibility in how databases are organized and used. Local offices can create, manage and use their own databases, and people at other offices can access and share the data in the local databases • To reduce telecommunications costs, some organizations build a replicated database: A database that holds a duplicate set of frequently used data.
Online analytical processing (OLAP) • Online analytical processing (OLAP) Software that allows users to explore data from several perspectives. • These programs are now being used to store and deliver data warehouse information efficiently. • The value of data ultimately lies in the decisions it enables. Powerful information-analysis tools in areas such as OLAP and data mining, when incorporated into a data warehousing architecture, bring market conditions into sharper focus and help organizations deliver greater competitive value.
Characteristic OLAP Data Mining
Purpose Supports data analysis and decision making
Supports data analysis and decision making
Type of analysis supported
Top-down, query-driven data analysis Bottom-up, discovery-driven data analysis
Skills required of user
Must be very knowledgeable of the data and its business context
Must trust in data-mining tools to uncover valid and worthwhile hypotheses
Visual, Audio and Other Database Systems • Organizations are increasingly finding a need to store large amounts of visual and audio signals in an organized fashion. These database systems help with the organisation and increases the efficiency of users by being able to recognise pictures or barcodes • Spatial data technology involves using a database to store and access data according to the locations it describes and to permit spatial queries and analysis
The use of a Distributed database
INF Chapter 6- Computer Networks
Principles • Effective communications are essential to organizational success • Communications technology lets more people send and receive all forms of information over great distances • The Internet is like many other technologies –it provides a wide range of services, some of which are effective and practical for use today, others are still evolving, and still others will fade away from lack of use
6.1 Telecommunications • Telecommunications refers to the electronic transmission of signals for communications, by such means as telephone, radio and television • Impacts businesses greatly because it lessens the barriers of time and distance, thus changing the nature of commerce itself • As networks are connected with one another and transmit information more freely, a competitive marketplace demands excellent quality and service from all organizations • An important characteristic of telecommunications is the speed at which information is transmitted- called the channel bandwidth which is measured in bits per second (bps). • Broadband communications- a very high rate of data exchange is possible. • Narrowband communications- supports a much lower rate of data exchange than broadband.
A general model of telecommunications 1. A sending unit, such as a person, a computer system, a terminal or another device, that originates the message. 2. A sending unit that transmits a signal 3. Signal transmitted to telecommunications device (a hardware component that facilitates electronic communication) 4. The telecommunications device then sends the signal through a medium (any material substance that carries an electronic signal to support communications 5. Another telecommunications device (5) connected to the receiving computer (6) receives the signal 6. The process can be reversed, and the receiving unit (6) can send another message to the original sending unit (1)
Synchronous and asynchronous communication • Advances in telecommunications technology allow us to communicate rapidly with clients and co-workers almost anywhere in the world. • With synchronous communication, the receiver gets the message almost instantaneously, when it is sent such as a phone call • With asynchronous communication (such as e-mail) there is a measurable delay between the sending and receiving of the message, sometimes hours or even days.
Guided Transmission Media Types
• Twisted-pair wire-classified by category, depending on the frequency of data transmission. • Coaxial cable- offers cleaner and crisper data transmission and higher transmission rate • Fiber-optic cable- high-intensity light beams are generated by lasers and are conducted along the transparent fibres. • Broadband over power lines- users connect their computer to a special hardware device that plugs into any electrical wall socket.
Wireless Transmission Media Types • Microwave: ? High-frequency (300 MHz–300 GHz) signal sent through the air ? Terrestrial (Earth-bound) microwaves are transmitted by line-of-sight devices, line must be unobstructed ? Microwave stations are placed in a series, max 30 miles apart ? A communications satellite, broadcasting over large geographic regions, also operates in the microwave frequency range ? The satellite receives the signal from the Earth station, amplifies the relatively weak signal and then rebroadcasts it at a different frequency ? A Geostationary satellite orbits the Earth directly over the equator ? Low earth orbit (LEO) satellite system employs many satellites, placed widespread ? A very small aperture terminal (VSAT) is a two-way satellite ground station with a dish antenna smaller than three metres in diameter • 3G and 4G wireless communication ? Evolved through four generations of technology and service ? 1G- 1980’s (analogue communications), 2G-1990’s (fully digital) ? 3G- supports voice and broadband data communications in a mobile environment at speeds of 2–4 Mbp ? (ITU) has defined 4G as a network that has meaningful improvement over 3G- delivers enhanced versions of multimedia • WiFi ? A medium-range wireless telecommunications technology brand owned by the Wi-Fi Alliance. ? The hardware’s wireless adapter that translates data into a radio signal and transmits it using an antenna
• Near Field Communication ? A very short-range wireless connectivity technology designed for consumer electronics, smartphones and credit cards- exchanges data in close proximity • Bluetooth ? a wireless communications specification that describes how smartphones, computers, printers and other electronic devices can be interconnected over distances of a few metres at a rate or about 2Mbps. • Ultra-wideband ? a form of short-range communication that employs extremely short electromagnetic pulses lasting 50 to 1000 picoseconds that are transmitted across a broad range of radio frequencies or several gigahertz • Infrared Transmission ? sends signals through the air via light waves at a frequency of 300 GHz and above. ? requires line-of-sight transmission and short distances ? e.g. Apple remote
Telecommunications Hardware • Modems ? A telecommunications hardware device that converts (modulates and demodulates) communications signals so they can be transmitted over the communication media. • Multiplexer ? A device that encodes data from two or more data sources onto a single communications channel, thus reducing the number of communications channels needed and therefore lowering telecommunications costs. • Front-end processors ? A special-purpose computer that manages communications to and from a computer system serving hundreds or even thousands of users. • Private branch exchange (PBX) ? A telephone switching exchange that serves a single organization. ? This sharing reduces the number of trunk lines required, which in turn reduces the organization’s telephone costs • Switches, Bridges, Routers and Gateways ? Switch- uses the physical device address in each incoming message on the network to determine to which output port it should forward the message to reach another device on the same network. ? Bridge- connects one LAN to another LAN that uses the same telecommunications protocol. ? Router- forwards data packets across two or more distinct networks towards their destinations, through a process known as routing. ? Gateway- serves as an entrance to another network.
6.2 Networks and distributed processing • Computer network-The communications media, devices and software needed to connect two or more computer systems and/or devices. • The computers and devices on the networks are called network nodes • Nodes can share data, information, and processing jobs • Networks enable geographically separated workgroups to share information, which fosters teamwork, innovative ideas, and new business strategies.
Network types • Personal Area Networks (PAN)- A network that supports the interconnection of information technology within a range of three metres or so. • Local Area Networks (LAN)- A network that connects computer systems and devices within a small area, such as an office, home or several floors in a building, is a LAN
• Metropolitan area network (MAN)- A telecommunications network that connects users and their devices in a geographical area that spans a campus or city, with a span of roughly 100 km • Wide area network (WAN)- A telecommunications network that ties together large geographic regions, used when one makes a long-distance phone call or access the Internet • International Networks- A network that links users and systems in more than one country- must meet specific national and international laws regulating the electronic flow of data across international boundaries, often called transborder data flow. Countries with less strict rules are called havens. • Mesh networking- A way to route communications between network nodes (computers or other devices) by allowing for continuous connections and reconfiguration around blocked paths by ‘hopping’ from node to node until a connection can be established. Full mesh topology- all nodes are connected directly to each other. Partial mesh topology- all the nodes are not connected
Distributed Processing • Centralized processing ? All processing occurs in a single location or facility. ? This approach offers the highest degree of control because a single centrally managed computer performs all data processing • Decentralized processing ? Processing devices are placed at various remote locations. ? Each computer system is isolated and does not communicate with another system • Distributed processing ? computers are placed at remote locations but connected to each other via telecommunications devices. ? One benefit of distributed processing is that managers can allocate data to the locations that can process it most efficiently.
Client/Server Systems • Users can share data through file server computing, which allows authorized users to download entire files from certain computers designated as file servers. • After downloading data to a local computer, a user can analyze, manipulate, format and display data from the file • Client/server- An architecture in which multiple computer platforms are dedicated to special functions such as database management, printing, communications and program execution. • Each server is accessible by all computers on the network.
Communications Software (not mentioned in slides) • Network operating system (NOS)- Systems software that controls the computer systems and devices on a network and allows them to communicate with each other- performs the same types of functions for the network as operating system software does for a computer • Network-management software- Software that enables a manager on a networked desktop to monitor the use of individual computers and shared hardware (such as printers), scan for viruses and ensure compliance with software licences; simplifies the process of updating files and programs on computers on the network • Fault detection and performance management are the two types of network-management products that employ the Simple Network Management Protocol (SNMP)
Securing Data Transmission (not mentioned in slides) • Encryption- The process of converting an original message into a form that can be understood only by the intended receiver. • Encryption key- A variable value that is applied (using an algorithm) to a set of unencrypted text to produce encrypted text or to decrypt encrypted text. • Securing Wireless Networks- Wired equivalent privacy (WEP) and Wi-Fi Protected Access (WPA) are the two main approaches to securing wireless networks such as wi-fi and WiMAX • Steps to safeguard a wireless network 1. Change default password on router 2. Create a service set identifier (SSID) that differentiates one network from another 3. Disable SSID Broadcasting 4. Set the security on the router to WPA
Virtual Private Network (VPN) (not mentioned in slides) • Virtual private network (VPN)- A private network that uses a public network (usually the Internet) to connect multiple remote locations. • VPNs support secure, encrypted connections between a company’s employees and remote users through a third-party service provider.
6.3 The Internet • The Internet is the world’s largest computer network • Actually, it is a collection of interconnected networks, all freely exchanging information • Nobody knows exactly how big the Internet is because it is a collection of separately run, smaller computer networks • ARPANET-A project started by the US Department of Defence (DoD) in 1969 as both an experiment in reliable networking and a means to link DoD and military research contractors, including many universities doing military-funded research- earliest form of the internet. • Internet Protocol (IP)- A communication standard that enables traffic to be routed from one network to another as needed.
How the Internet Works 1. The Internet transmits data from one computer (called a host) to another 2. If the receiving computer is on a network to which the first computer is directly connected, it can send the message directly 3. If the receiving and sending computers are not directly connected, the sending computer relays the message to another computer which forwards it on 4. A message can pass through a dozen or more forwarders on its way from one part of the Internet to another, thus if some nodes on the Internet are down, messages can still be sent via another route
General terminology • The various networks that are linked to form the Internet pass data around in chunks called packets, each of which carries the addresses of its sender and its receiver. • The set of conventions used to pass packets from one host to another is known as the Internet Protocol (IP) • Transmission Control Protocol (TCP)- The widely used transport-layer protocol that most Internet applications use with IP. • After a network following these standards links to a backbone – one of the Internet’s high-speed, longdistance communications links – it becomes part of the worldwide Internet community. • Uniform resource locator (URL)- An assigned address on the Internet for each computer. • The ‘http’ specifies the access method and tells your software to access a file using the Hypertext Transport Protocol. • The ‘www’ part of the address signifies that the files associated with this website reside on the World Wide Web server • Internet service provider (ISP)- Any company that provides people or organizations with access to the Internet.
Internet Applications The World Wide Web • World Wide Web- A collection of tens of thousands of independently owned computers that work together as one in an Internet service. • Developed by Tim Berners-Lee at CERN, the European Organization for Nuclear Research in Geneva • The web is a menu-based system that uses the client/server model. • Hypertext- Text used to connect web pages, allowing users to access information in whatever order they wish. • Hypertext Markup Language (HTML)- The standard page description language for web pages. • HTML tags- Codes that let the web browser know how to format text – as a heading, as a list, or as body text – and whether images, sound or other elements should be inserted. • Extensible Markup Language (XML)- A newer markup language for web documents containing structured information, including words, pictures and other elements.
Web Browsers • Web browser- Software that creates a unique, hypermedia-based menu on a computer screen, providing a graphical interface to the web. • Hypermedia- An extension of hypertext where the data, including text, images, video and other media, on web pages is connected allowing users to access information in whatever order they wish. • Applets- A small program embedded in web pages- allowed to run by web browsers
Search Engines and Web Research • Search engines-A web search tool that eases the finding of information • Search engines that use keyword indexes produce an index of all the text on the sites they examine.
Web Programming Languages • Java- An object-oriented programming language from Sun Microsystems based on C++ that allows small programs (applets) to be embedded within an HTML document. • Ruby on Rails is a popular software framework for developing web applications that is optimized for programming productivity.
Developing Web Content • A web page must be created, then content must be placed on it for others to access, and then a content management system (CMS) must be implemented to keep the website running smoothly. • Web hosting services provide space on their websites for people and businesses that don’t have the financial resources, time or skills to host their own website
• Some web developers are creating programs and procedures to combine two or more websites into one website, called a ‘mash-up’
Web Services • Web services- Standards and tools that streamline and simplify communication among websites for business and personal purposes. • XML is used within a web page to describe and transfer data between web service applications • Besides XML, three other components are used in web service applications: 1. SOAP (Simple Object Access Protocol)- a specification that defines the XML format for messages. 2. WSDL (Web Services Description Language)- provides a way for a web service application to describe its interfaces in enough detail to allow a user to build a client application to talk to it. 3. UDDI (Universal Discovery Description and Integration) is used to register web service applications with an Internet directory
Developing Web Content and Applications • Popular tools for creating web pages: Adobe Dreamweaver, Microsoft Expression Web and the open source alternative Nvu • Such software allows users to create web pages using an interface similar to a word-processor. • The software converts what the user types into HTML code and creates hyperlinks to connect the pages
Other internet applications • Email- A method of sending communications over computer networks. • Telnet- A terminal emulation protocol that enables users to log on to other computers on the Internet to gain access to public files. • File Transfer Protocol (FTP)- A protocol that describes a file transfer process between a host and a remote computer and allows users to copy files from one computer to another. • Cloud computing- refers to a computing environment where software and storage are provided as an Internet service and accessed with a web browser.
6.5 Intranets and Extranets • An intranet is an internal company network built using Internet and World Wide Web standards and products that employees use to gain company information • An intranet is an inexpensive yet powerful alternative to other forms of internal communication, including conventional computer setups • All sorts of documents can be inexpensively converted to electronic form on the web and be constantly