itft-system analysis and design
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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.