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INTRODUCTION TO INFORMATION SYSTEMS

1.0 Definitions

System

A system is a set of inter-dependent/interrelated components (some of which may be systems in their own right), with an identifiable boundary and which collectively accomplish certain objectives/purpose.

Characteristics of a system

A system has 9 characteristics.

1. Components

A system is made up of components. A component is an irreducible part or aggregation of that make up a system, also called subsystems. We can repair or upgrade the system by changing individual components without having to make changes throughout the entire system.

2. Interrelated Components

The components are interrelated. This means the dependence of one subsystem on one or more subsystems. The function of one subsystem is tied to the function of others.

3. A Boundary

A system has a boundary within which all of its components are contained and which establishes the limits of a system, separating the system from other systems. The boundary is the line that makes the inside and outside of a system and that sends off the system from its environments.

4. A purpose

This is the overall goal or function of a system. A system must give priority to the objectives of the organization as a whole as compared to the objectives of a subsystem.

5. An Environment

This is everything external to a system that interacts with the system i.e. everything outside the system’s boundary, usually the system interacts with its environment, exchanging, in the case of an information system, data and information.

6. Interfaces

This is the point of contact where a system meets its environments or where subsystems meet each other. eg. The interface between an automated system and its users (manual system) and interfaces between different information systems. It is the design of good interfaces that permits different systems to work together without being too dependent on each other....