An information system is an organized collection of data, equipment, procedures, and people involved in the acquisition, storage and processing of data to produce information needed in the management of an organization.
The hardware is the physical equipment which includes the computer and other related devices. These devices include the central processing unit, storage devices and output devices. Regardless of the size or cost of the system, all computers consist of these components. The most important element of the computer is the Central Processing Unit (CPU), which consist of an arithmetic logic unit, a control unit, and a memory section. The arithmetic logic unit carries out all arithmetic logic unit carries all arithmetic activities, while the control unit manages this process. The main memory of the computer system stores data and instructions to be used in data processing. The input devices are for entry of data into the computer for processing and storage and include keyboards, optical bar-code scanners (like those used in supermarkets), or optical scanning machines (like those used to sense pencil marks on examination sheets). Output devices display information and present the processing results to the user of the system.
Most computers are general purpose machines that can perform a variety of tasks, such as computing the amount of pay for an individual, or keeping track of inventory levels. What makes the hardware capable of these various activities is the software, the set of programs documents, procedures and routines associated with the operation of a computer system. Computer software is written on programming languages.
The underlying element in all information systems activity is the data. Managing the data in information systems is such an important task that organizations often hire specialists, called data managers. They ensure that procedures are followed to verify correctness of data when it is stored. Similarly, they provide the guidelines for storage and retrieval of data in files and data bases. A data base management system is software that allows an organization to build, manage, and provide access to its stored data. Without accurate and accessible data, computers information systems would be useless.
A critical component of a management information system is the set of procedures for sustaining the system. The usefulness and success of the system is determined by the procedures. Among the essential system procedures re the following:
Data Entry and Validation: Inaccurate or incomplete data of little value to management and may produce disastrous results if used in decision making. The data entry and validation system captures and verifies data for accuracy and completeness.
Data Management: Standards and procedures for storage and preservation of data are determined. This minimizes redundancy of data and provides for uniformity of details for all uses.
Security and Integrity: This system ensures that the data will be safeguard from loss or destruction and only authorized individuals are allowed to access the system. It controls actions that can be taken by individuals for entry, retrieval, or data in the system.
Lack of adequate procedures can hamper the value of the system to the organization, as procedures are a very important component in the information system.
Development of information systems:
Development of computer based information systems can be difficult and expensive, particularly when the applications are large and complex. The resulting systems often spew out errors that cause serious business problems. Because of the disastrous dimension of such problems, as well as the strategic value of information technology, managers must have at least a general knowledge of what is involved in information systems development. There are several alternatives to systems development. Some of them are: systems life cycles, applications software, Prototyping and user development systems.
This is the process of building a rough working model of a proposed information system.
Prototyping is the process of building rough, working model of all or parts of a proposed information system. Unlike the traditional approach, where all the user needs are to be clearly specified in the early stages only, in prototyping user specifications are loosely defined. The system then goes through a number of modifications and enhancement before it finally meets the user requirements. Such systems usually earn better acceptance from users because they meet user’s specific needs.