CH 2
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utpalsaha221CH 2
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utpalsaha221System Analysis
Design
Chapter 2
Systems Analysis
and Life Cycle
Learning Goals
1. Nine Steps in designing Information
Systems.
2. Tasks performed in each step.
3. Nature of tasks performed by Systems
Analysts.
4. The attributes of Systems Analysts.
5. The tools used by Systems Analysts.
Life Cycle of Systems Analysis and Design
❑ Nine Steps involved in Analysis and Design
1. Requirements Determinations
2. Requirements Specifications
3. Feasibility Analysis
4. Final Specifications
5. Hardware Study
6. System Design
7. System Implementation
8. System Evaluation
9. System Modification
Life Cycle of Systems Analysis and Design
❑ Step 1 : Requirements Determination
▪ Arrived at by a consensus among
managers
▪ Priorities among applications determined
▪ Pick high priority applications.
Life Cycle of Systems Analysis and Design
❑ Step 2 : Requirements Specification
▪ Known as System Requirements Specification
(SRS)
▪ Understand the existing System
▪ Applications where a system is required are
listed
▪ Arrive at the specifications of the users’
Requirements after discussions with the user
▪ A system may encompass several applications
Life Cycle of Systems Analysis and Design
❑ Step 3 : Feasibility Analysis
▪ Formulate Goals of the system and quantify
goals
▪ Find alternative methods of meeting the goals
▪ For each alternative assess resources needed
• Human Resources
• Time and Money
• Equipment needed
▪ Assess cost of each alternative
▪ Find the best alternative method subject to
resource constraints
Life Cycle of Systems Analysis and Design
❑ Step 4 : Final Specifications
▪ Specifications would state what the system would
achieve.
▪ Specification drawn up are improved for
implementation.
▪ SRS written- given to user and agreement
reached
Life Cycle of Systems Analysis and Design
❑ Step 5 : Hardware Study
▪ Determine Hardware and Software required
to execute the application.
▪ Determine Response time,Volume of data to
be processed, Frequency of reports etc & then
pick the hardware.
Life Cycle of Systems Analysis and Design
❑ Step 6 : System Design
▪ Logical Design of the System
▪ Objects Identified
▪ Database Designed
▪ Program Specification drawn up
▪ Implementation Plan Drawn up
▪ Test Plan
Life Cycle of Systems Analysis and Design
Step 7 : System Implementation
▪ Write Programs
▪ Create Database
▪ Document System
▪ Train Users
▪ Trial run of the system
▪ Test and Accept
Life Cycle of Systems Analysis and Design
❑ Step 8 : System evaluation
▪ Find out from Users whether the System
meets specified requirements.
▪ List areas of dissatisfaction and find reasons
▪ Suggest if there has to be any improvements to
the system
Life Cycle of Systems Analysis and Design
❑ Step 9 : System Modification
▪ Fix errors
▪ Add/Delete features as required by users
▪ Tune the System
▪ Continuously monitor system and assess
performance
System Life Cycle Diagram Revised Prioritized
User Requirements Specifications
Requirements
Feasibility
Requirements Requirements
Analysis
Determination Specification
Decision to Test Plan
Design Information Feasibility
System Logical Functional Study
Design Specifications System
System System
Implementation Design Specification
Analysis
System Configuration Physical
Data Requirements
System
Evaluation Hardware
Study Budget & schedule
Revised
Requirements
System
Maintenance Improved System
Roles of Systems Analyst
❑ Defining Requirements
- Involves Interviewing Users
❑ Prioritizing Requirements
- Obtain Users Consensus
❑ Fact Gathering
-Data, Facts, Opinions of Managers
-Lower level Users should be consulted
Continue…
❑ Analysis and evaluation
- Arrive at appropriate system
❑ Solving problems
- Hazy requirements converted into
specific requirements
- Suggest many alternative solutions
- Quantify cost and benefits
Continue…
❑ Drawing up Specifications
-Functional Specifications
- Understood by users and programmers
- Accepted by users
- Precise and detailed
- Account for possible changes
Continue…
❑ System Design
▪ Logical design of system
- Objects identification
- Normalizing database
- Test plan
▪ Design must be modular to accommodate change
Continue…
❑ Evaluating Systems
- Evaluation after use for sometime
-Plan periodicity for evaluation
-Modify as needed
Attributes of a Systems
Analyst
❑ KNOWLEDGE OF ORGANISATION
-Knowing user’s jargon & practices
-Know Management functions.
❑ KNOWLEDGE OF COMPUTERS AND SOFTWARE
-Knowledge of system design tools
-Keep abreast of modern developments
Continue…
❑ GOOD INTERPERSONNAL RELATIONS
-Need to work as team member
-Lead smaller teams
-Interface with programmers & Users
-Motivator.
❑ ABILITY TO COMMUNICATE
-Oral Presentation
-Report Writing
-Answer queries
Continue…
❑ ANALYTICAL MIND
-Problem solving attitude
-Ability to assess trade offs
-Sound commonsense
-Curiosity to learn about new organizations
❑ BREADTH OF KNOWLEDGE
-Broad Liberal Knowledge
-Variety of jobs to be tackled in diverse organizations
Tools used by Systems
Analyst
❑ Data Flow Diagram
❑ Decision Tables
❑ Modeling Language such as UML
❑ Normalization of Databases
❑ Testing tools
❑ ISO/CMM procedure manuals