Information System (IS)

· A system is a set of components that work together to achieve a common goal. A system accepts input, processes it, and produces an output. A system is composed of one or more subsystems. A system may be a closed system or an open system. A closed system is a stand- alone system that does not interact with other systems. An open system interacts with other systems.

                                     A system

· Information System (IS) is a set of inter-related components that (1) collect data, (2) manipulate data, (3) disseminate data and information, and (4) provide feedback to meet an objective. An information system uses resources like people, hardware, software, data, and networks to perform input, processing, output, storage, and control activities. Some examples of IS are ATMs, railway reservation system, and movie ticket reservation systems.

Components of Information System: An IS consists of four main components—Input, Process, Output, and Feedback. Input is the activity of gathering and capturing raw data. A process converts or transforms data into useful output. During processing, the input data is manipulated into information using mathematical, statistical, and other tools. Output is the generation and presentation of useful information, usually in the form of documents and reports. Feedback is an output that is used to make changes to the input, or the processing activities.

                        Components of informationsy system

Information systems are needed both by the people and the business organizations. People need information system for entertainment and enlightenment. Organizations require information systems to support decision making, coordination, problem solving and control. Information systems may also help to analyse problems, and to create new products.

Characteristics of IS: Like any other system, ISs have seven characteristics

                             Characteristics of information system

· Environment is anything outside the system.

· Boundary separates the system from environment. Any part within boundary is the system and outside boundary is the environment.

· Input is the data from environment to the system. The system uses the input.

· Output is the information from the system to the environment. The system uses input to generate output.

· Components are the subparts of the system.

· Interrelationships are the associations between components of a system.

· Interface is a mechanism for interaction between different components of the system

· The performance of Information System is measured by its efficiency and effectiveness. Efficiency is a measure of what is produced divided by what is consumed. Effectiveness is the extent to which a system attains its goals.

· The role of the Information System is expanding and evolving continuously. In 1950s— 1960s, the focus was on data processing. Management reporting and decision support was provided during 1960s-1970s and 1970s-1980s, respectively. 1980-1990s saw it being also used for strategic and end user support. Lately in 1990s-2000s, there is a shift towards global internetworking.

· An information system can be manual and computerized.

Here, we shall focus on the computerized information system or the Computer-based Information System.