system concept 4.ppt

Concept of Information Systems

system• A set of interacting components that

operate together to accomplish a purpose

What is a SYSTEM?

• A system is a group of interrelated components working together toward a common goal by accepting inputs and producing outputs in an organized transformation process.

S1S2

S3S4

Systems structure

Subsystems

Systems Boundary

Environment

Systems Input Output

Abstract Concept of a Systems

INPUT OUTPUTPROCESS

FEEDBACK

System properties

• A system has– Purpose– Boundary– Environment– Inputs– Outputs

Example: a manufacturing system

INPUTof raw materials

OUTPUT of finished products

Manufacturing

PROCESS

Control byManagement

Control signals

Control signals

Feedback signals

Feedback signals

System Boundary

Environment

What is an Information Systems?

• An information system can be any organized combination of people, hardware, software, communications network, and data resources that collects, transforms, and disseminates information in an organization

Components of an Information System

Control

Input Process

Memory

Output

DataPeople

Software

network

computer

Information Systems Activities

• Input of Data– Manual input by key, scanning, sound, image,…

• Processing of Data into Information– Calculate, sort, find, report, disseminate……

• Output of Information Products– Report, display, suggestion, ……

• Storage of Data Resource– Database, data file, maintenance, …..

• Control of System Performance– Audit, ……

Phases in building and maintaining systems

• Initiation

• Development

• Implementation

• Operation & Maintenance