What is an Information System? An information system involves the effectiveness use of people, processes, hardware, software, networks and technology to help achieve a company’s goals and objectives. An Information System involves using the above resources to transform data into information. An information system can be manual or computerised, although as a result of the increasing speed and efficiency of computers, there are very few organisations today that would not have at least one computers in operations. Types of Information Systems Operational Systems Operational systems involved in the introduction of a computer based system to the business environment. This system processes the data produced day to day business transactions of a company or business. Transactions such as the ordering of stock, customer invoicing and billing.
Expert systems An expert system is a form of Artificial Intelligence (AI) that combines the knowledge base on human reasoning and the use of extremely powerful computers. While expert systems seem to be thinking on their own they are limited by their programming. Expert systems are used in many different places an example is the fuel injection of a car. Managing Information Systems Managing information systems was introduced as the result of Operations Systems. A Management Information System is a computer based system that produces information for top-level, middle-level and lower-level management that is both accurate and timely. Decision Support Systems A Decision Support System consists of a group of people and procedures as well as a set of programmes sharing data and information.
A DSS is oriented around effective decision making within the business. Executive Information Systems An Executive Information System supports the internal and external information requirements of top-level managers. It features the capabilities of both Decision Support Systems and Management Information Systems, hence giving far greater flexibility and support. Office Systems As the name suggests, this system involves most of the employees. An Office System includes LANs, WANs, e-mail, Internet, voice mail, word processing, database management, spreadsheets, desktop publishing, and intranets. Purposes of Information Systems The purpose of an Information System is obviously dependant upon the organisation that uses the information system, and hence the requirements for that Information System.
For instance an information system is used in a library to keep record of all books, videos and CD’s that are available. In a machinery plant such as Ford Motors the information system used there would be a sophisticated system that would detail how to build cars. Management of Information Systems The management of information is one of the largest areas of concerns for companies and organisations. It is easy to appoint or sub-contract an analyst to look at the current system; design a new information system for you, or to code the new system and implement it for you. The CEO’s of a company or organisation usually have the higher base of power among the information system. Central Processing Unit The central processing unit is most commonly known as the ‘processor’, which is where the majority of the computer’s work is done.
There are two major characteristics of the CPU which determine the power at which the CPU runs. First the clock speed is measured in Megahertz. Each computer instructions requires a fixed number of cycles, so the clock speed determines how many instructions per second the microprocessor. Word size is also a major determinant on the amount and speed of data that a CPU.
The Control Unit The control unit is part of the computer hardware that locates, analyses and executes the appropriate data operation. It contains circuitry that uses electrical signals to directs other parts of the system to execute programmes. RAM (Random Access Memory) RAM refers to a group of memory chips that function as the computer’s primary work place. It determines the number and size of programmes that can be run at the same time, and the amount of data that can be processed at any given point.
The ‘random’ information both before and after it. Information is stored in RAM chips. The two types of RAM are DRAM and SRAM. The main difference between the two is in the technology they each hold in the data.
SCSI (Small Computer System Interface) SCSI ports allow computers to communicate with peripheral devices in a faster and more flexible manner than the basic serial and parallel interfaces. SCSI interfaces currently employ a parallel interface. This form of data transfer is a more flexible. USB (Universal Serial Bus) USB allows you to connect devices to computers of different platforms without having to buy expensive converter plugs. It supports data transfers of up to 12 Mbps, and one USB port can support up to 127 peripheral devices such as keyboards, mice, printers, scanners, digital cameras and modems.
FireWire (IEEE 1394) FireWire ports are a faster and more expensive version of USB. They were originally developed by Apple and Texas Instruments and can do all things that USB ports can do, but at a much faster rate of up to 3, 200 Mbits/ sec. Bandwidth Bandwidth is the transmission capacity of an electronic line such as a network, computer bus or channel. The value of bandwidth is measured in bits per second.
Local Area Network (LAN) The LAN is made up of a collection of servers, workstations, a network operating system and communication links within the same geographic area. LAN’s are used to connect computer resources to each other. WAN (Wide Area Network) A WAN is a series of interconnected LANs spread over a wide geographical area, such as across a city, state or country. WAN networks are used in large offices which have departments spread across different locations separated by reasonable distances.
Hybrid A hybrid can be formed by using elements from two or more of the common topologies.