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L5 Sod System-Analysis-And-Design

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L5 Sod System-Analysis-And-Design [1] Module: SFDAD501-SYSTEMS ANALYSIS AND DESIGN Competence: SFDAD501-Perform systems analysis and design Sector: ICT Trade: Software Development Level: 5 LU1: Describe information systems concepts LO 1.1. Identify information systems Context of Information system: Data is unprocessed facts and figures without any added interpretation or analysis. "The price of crude oil is $80 per barrel." Information is data that has been interpreted so that it has meaning for the user. "The price of crude oil has increased from $70 to $80 per barrel" gives meaning to the data and so is said to be information to someone who tracks oil prices. Knowledge : *is a combination of information, experience and insight that may benefit the individual or the organization. *is the state of knowing about or being familiar with something. Systems categories with examples The systems can be divided into two categories namely: i. Natural systems ii. Artificial systems i. Natural Systems Natural systems are systems that have not been established by man. They exist in nature to accomplish their goals. These systems are divided into three categories: Stellar Systems: galaxies (the very large group of stars in the universe), solar system etc... Geological systems: rivers, mountains etc... Molecular systems: organization of complex atoms [2] Natural systems can be divided into two parts: - Natural physical systems: these systems are interest of human beings because they look at any time how they can change them. They manufacture systems, some using computers that can easily interact with natural systems. (Not breath) - Living systems: they include the billions of animals and plants around us and humans. These systems can help to illustrate and understand the artificial systems. (Breath) It should be noted that artificial systems (automated) interact with living systems. In some cases, artificial systems are replacing systems alive. In other cases, researchers consider living systems as components of an automated system. ii. Artificial systems Definition: artificial systems are systems made by people. Those systems are divided into five systems which are: - Social systems: organizations, doctrines, etc… - Transportation Systems: networks of highways, air transport and so on. - Communication systems: telephone, telefax etc… - Industrial systems: mining, assembly lines etc… - Financial Systems: Accounting, inventory, ledgers etc… Most of these systems use computers today. INFORMATION SYSTEMS Information Systems is an academic study of systems with a specific reference to information and the complementary networks of hardware and software that people and organizations use to collect, filter, process, create and also distribute data. Examples: There are various types of information systems, for example: transaction processing systems, decision support systems, knowledge management systems, learning management systems, database management systems, and office information systems. [3] Components of Computer based Information System (CBIS). (“IS features”) The automated systems are artificial systems that interact with or controlled by one or more computers. o Computer hardware: physical, tangible parts or components of a computer, such as the central processing unit (CPU), monitor, keyboard, computer data storage, graphics card, sound card, speakers and motherboard. o Software: program that enables a computer to perform a specific task and allow the hardware to process the data. Eg: operating systems, database systems, data structures, procedures or controls required. o Data: it is the information the system stores and may return at any time. o Networks: are a connecting system that allows diverse computers to distribute resources. o People: those who interact with the system, who provide inputs and outputs that use an automated system and those who do manual handling activities in the system. In short, people are users and operators of the hardware and software system. o Procedures: are the commands for combining the components above to process information and produce the preferred output. The first four components (hardware, software, data and network) make up what is known as the information technology platform. Systems features and characteristics [4] a) Objective b) Standards c) Environment d) Feedback e) Boundaries f) Interfaces a) Objective Something which you plan to do or achieve. Every system has a predefined goal or objective towards which it works. A system cannot exist without a defined objective. For example, an organization would have an objective of earning maximum possible revenues, for which each department and each individual has to work in coordination. b) Standards A moral rule which should be obeyed. It is the acceptable level of performance for any system. Systems should be designed to meet standards. Standards can be business specific or organization specific. c) Environment Every system whether it is natural or artificial (man-made) co-exists with an environment. It is the source of external elements that impose on the system. In fact, it often determines how a system must function. Also, for a system to exist it should change according to the changing environment. For example, we humans live in a particular environment. As we move to other places, there are changes in the surroundings but our body gradually adapts to the new environment. If it were not the case, then it would have been very difficult for human to survive for so many thousand years. d) Feedback Information or statements of opinion about something, such as a new product, that provide an idea of whether it is successful or liked. Feedback is an important element of systems. Feedback measures output against a standard in some form of cybernetic procedure that includes communication and control. Feedback may be positive or negative. [5] e) Boundaries A system should be defined by its boundaries - the limits that identify its components, processes, and interrelationships when it interfaces with another system. f) Interfaces Interfaces are another important element through which the system interacts with the outside world. System interacts with other systems through its interfaces. Users of the systems also interact with it through interfaces. Therefore, these should be customized to the user needs. Functions of environment of IS with examples An information system has four functions namely: - Input - Process - Output - Control/ Feedback Input (Entries): the information entered into a computer system. This task is performed by personnel entering through input devices (such as keyboard, mouse, scanner, microphone, etc) and storage media (flash disk, hard disk, memory card, etc). Automatic processing: the process of transforming input information into and output. It is performed by the computer. A process is a function which transforms data into information. More complex processes are the functions that perform calculations and can make assumptions about missing data in order to create information from the data available. The full automatic processing can be divided into the following 4 categories: -Controls: who are to validate the entered data and reject data that do not meet the constraints of the model, -Updated: adding new data, some data changes or cancellations of certain data. -Research: consists in selecting from the database of information, those who meet certain criteria. [6] -Calculations: that is to provide, develop new data from the data entered or stored according to specific rules that are in the computer memory. Output: the visual, auditory, or tangible perceptions provided by the computer after processing the provided information. Is to make information accessible to the world outside. Example: Printing a newsletter, which will generate the files used by other systems (printer), speaker, projector, etc. Control: The control elements guide the system. It is the decision-making subsystem that controls the pattern of activities governing input, processing, and output. A feedback / control loop is what happens to output when it is processed and produced. The system continuously repeats the same processes depending on the output of the last loop which can then impact on the input of the next data in to the loop. For example, if a business might want to buy stock from a supplier if the stock level reaches 10. The system might check stock levels every hour (in a loop) and if the stock level is above 10, the loop continues without action until the point it hits 10 or under at which stage the command gets executed and new stock is ordered. Data deposit: The memory is the function of storing information. It is storing programs, data structures and data storage (Eg: Hard disk drive, flash disk, Memory-card, etc). Types of IS hierarchy i. Office Automation IS ii. Transaction Processing IS iii. Management IS iv. Decision support systems v. Expert systems i. Office Automation Systems (OAS) OAS are systems that try to improve the efficiency of employees who need to process data and information. The best example is the wide range of software systems that exist to improve the productivity of employees functioning in an office (e.g. Microsoft Office, email, etc). ii. Transaction Processing Systems (TPS) [7] A transaction refers to any event or activity that affects the organization. A business will have many (sometimes several) TPS; e.g.: billing systems to send invoices and statements to clients; systems which calculate weekly or monthly payroll and tax payments;
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