An information system can be defined as a set of interrelated components that collect, process, store and distribute information to support decision making and control in an organization. It can be any organized combination of people, hardware, software, communication networks, data resources, policies and procedures that store, retrieves, transforms and disseminate information in an organization.
Components of an information system
- People – These use the system to fulfil their informational needs. They include end users and operations personnel such as computer operators, systems analysts, programmers, information systems management and data administrators.
- Computer Hardware – Refers to physical computer equipment and devices, which provide for five major functions.
- Input or data entry
- Secondary storage for data and programmes
- Central processor (computation, control)
- Computer Software – Refers to the instructions that direct the operation of the computer hardware. It is classified into system and application software.
- Telecommunication System/Communication network
- Databases – Contains all data utilised by application software. An individual set of stored data is referred to as a file. Physical storage media evidences the physical existence of stored data, that is: tapes, flash discs, CDs, cartridges and diskettes.
- Procedures – Formal operating procedures are components because they exist in physical forms as manuals or instruction booklets. Three major types of procedures are required.
- User instructions – for application users to record data, to use a terminal for data entry or retrieval, or use the result.
- Instructions for preparation of input by data preparation personnel.
- Operating instructions for computer operations personnel.