Systems Analysis and Design Presented by Thakur Rai
Definitions System - organized set of related components established to accomplish a certain task. Systems Analysis - process of studying an existing system to determine how it works and how it meets the users needs. Systems Design - process of developing a plan for an improved system based off of the results from the systems analysis.
Change People are inherently resistant to change Change Agent (System Analyst) User involvement is the vital Key to the success of the redesign. Why??
Systems Development Life Cycle Preliminary Investigation Analysis Design Development Implementation
Preliminary Investigation True nature of problem Problem scope Objectives Preliminary Investigation AnalysisDesignDevelopmentImplementation
System analysis Data gathering Written Documents, Interviews Questionnaires, Observation, Sampling Data analysis DFD (Data Flow Diagram) Charts, Tables System requirements Preliminary Investigation AnalysisDesignDevelopmentImplementation
Data Flow Diagram DFD Process - Actions taken on data File - Repository of data Source- Data origin outside system Sink - Destination for outgoing data Vectors - Shows flow of data
System Design 2 Phases Preliminary Design Phase The analyst establishes the new system concpet Detail Design The analyst determines exact design specifications Why???? To make sure management approves the overall plan before making a major investment Preliminary Investigation AnalysisDesignDevelopmentImplementation
Preliminary Design Could the system be outsourced? Should we purchase packaged software? Should we do in-house design? Prototype? Use of CASE Tools? Get the proposal Accepted! Preliminary Investigation AnalysisDesignDevelopmentImplementation
Detailed Design Comes after Preliminary Design Done after the proposal has been accepted. Input/Output Requirements Files & Databases System Processing System Controls & Backups Preliminary Investigation AnalysisDesignDevelopmentImplementation
Systems Development Programming Testing Unit - Test Units or Pieces of coding System - Use Test Data to test every part of the program to ensure compatibility Volume - Large volume of data Project Management Software - to allocate tasks and resources, Time Lines, Project Costs. Preliminary Investigation AnalysisDesignDevelopmentImplementation
Implementation Training Equipment Conversion File Conversion System Converion Auditing Evaluation Maintenance Preliminary Investigation AnalysisDesignDevelopmentImplementation
System Conversion Direct - All at once Phased - One step at a time Pilot - Entire system used by some users Parallel - simultaneous operations (Most prolonged and expensive)