System Analysis and Design

System’s Concept

• Term system is derived from the Greek word‘Systema’ which means an organizedrelationship among functioning units orcomponents.

Definition of System

• A system is an orderly grouping of interdependent components linked together according to a plan to achieve a specific objective.

Characteristics of a System

• Organization

• Interaction

• Interdependence

• Integration

• Central Objective

Characteristics of a System

• Organization-It implies structure and order.

• Interaction-It refers to manner in which eachcomponent functions with other componentsof the system.

• Interdependence-Units/parts are dependenton each other.

Characteristics of a System

• Integration-The parts of a system work together within the system even though each part performs a unique function.

• Central Objective-Objective may be real or stated. All the components work together to achieve that particular objective.

Elements of a System

• Outputs and Inputs

• Processor

• Control

• Feedback

• Environment

• Boundaries and Interface

Elements of a System

• Inputs and Outputs- Inputs are the elements that enter the system for processing and output is the result of processing.

• Processor- It is the element that involves the actual transformation of input into output.

Elements of a System

• Control- The control element guides the system.

• Feedback- Output is compared against performance standards.

• Environment- It is the suprasytem within which an organization operates.

• Boundaries and Interface- A system should be defined by its limits.

Types of System

• Physical – These are tangible entities thatmay be static or dynamic in operation. Forexample- parts of a computer center are thedesks, chairs etc. that facilitate operation ofthe computer. They are static and aprogrammed computer is dynamic.

Types of System

• Abstract System – These are conceptual ornon physical entities. For example- theabstract conceptualization of physicalsituations. A model is a representation of areal or planned system. A model is used tovisualize relationships.

Types of System

Deterministic System – It operates in apredictable manner and the interactionbetween parts is known with certainty. Forexample: Two molecules of hydrogen andone molecule of oxygen makes water.

Probabilistic System – It shows probablebehavior. The exact output is not known. Forexample: weather forecasting, mail delivery.

Types of System

Social System- It is made up of people. Forexample: social clubs, societies

Human Machine System- When bothhuman and machines are involved toperform a particular a particular task toachieve a target. For example:- Computer.

Machine System- Where humaninterference is neglected. All the tasks areperformed by the machine.

Types of System

• Natural System- The system which is natural.For example- Solar system, Seasonal System.

• Manufactured System- System made by manis called manufactured system. For example-Rockets, Dams, Trains.

Types of System

• Permanent System- Which persists for longtime. For example- policies of business.

• Temporary System- Made for specified timeand after that they are dissolved. Forexample- setting up DJ system

Types of System

• Adaptive System- respond to change in theenvironment in such a way to improve theirperformance and to survive. For example-Human beings, animals.

• Non Adaptive System-The system whichdoesn’t respond to the environment. Forexample- Machines

Types of System

• Open System – It has many interfaces with itsenvironment. It interacts across itsboundaries, it receives inputs from anddelivers outputs to the outside world. It mustadapt to the changing demands of the user.

• Closed System – It is isolated from theenvironmental influences. A completelyclosed system is rare.