It is a process of planning a new business system or replacing an existing system by defining its components or modules to satisfy the specific requirements. Before planning, you need to understand the old system thoroughly and determine how computers can best be used in order to operate efficiently.
System Design focuses on how to accomplish the objective of the system.
System Analysis and Design (SAD) mainly focuses on:
What is a System?
The word System is derived from Greek word Systema, which means an organized relationship between any set of components to achieve some common cause or objective.
A system is “an orderly grouping of interdependent components linked together according to a plan to achieve a specific goal.”
Constraints of a System
A system must have three basic constraints:
- A system must have some structure and behavior which is designed to achieve a predefined objective.
- Interconnectivity and interdependence must exist among the system components.
- The objectives of the organization have a higher priority than the objectives of its subsystems.
For example, traffic management system, payroll system, automatic library system, human resources information system.
Properties of a System
A system has the following properties:
Organization implies structure and order. It is the arrangement of components that helps to achieve predetermined objectives.
It is defined by the manner in which the components operate with each other.
For example, in an organization, purchasing department must interact with production department and payroll with personnel department.
Interdependence means how the components of a system depend on one another. For proper functioning, the components are coordinated and linked together according to a specified plan. The output of one subsystem is the required by other subsystem as input.
Integration is concerned with how a system components are connected together. It means that the parts of the system work together within the system even if each part performs a unique function.
The objective of system must be central. It may be real or stated. It is not uncommon for an organization to state an objective and operate to achieve another.
The users must know the main objective of a computer application early in the analysis for a successful design and conversion.
Types of System
1. Conceptual Systems
- Are theoretical and explanatory in the nature.
- Provide the much needed clarification.
- Provide theoretical framework for which there may or may not be any real life counterpart.
- E.g. of such systems can be philosophy, theology etc.
2. Empirical Systems
- Are very practical, specific and also very operational in the nature.
- Can be based on the conceptual system.
- Examination system, surgery act as very good examples of the empirical systems.
3. Open Systems
- Involve continuous interaction with the environment.
- So exchanges the information, material, energy with the environment.
- Is open and also self organizing in the nature.
- Is also adoptive or adaptive to the changing environment as it is flexible.
4. Closed Systems
- Shuns any kind of the exchange with the environment.
- Is rigid in nature.
- Is not at all amenable to the change.
- Is also self contained.
- Is somewhat isolated in the nature.
- Is having a well defined boundary.
- Is not at all adaptive in the nature.
5. Natural Systems
- Such Systems exist and also abound in the nature.
b. Are also not at all the results of the human endeavors.
c. Rivers, mountains, minerals etc. are the major examples of the natural Systems.
6. Artificial Systems
- Are manufactured (man made).
- Examples of such Systems are dams, canals, roads, machines, factories etc.
7. Probabilistic Systems
- Based on the predictability of the behavior or the outcome.
8. Deterministic Systems
- In such Systems, the interaction of the elements is known.
- As the behavior of the elements is pre determined, it becomes possible to work upon the reaction well in the advance.