3. System Development Life Cycle (SDLC)
• Development of Information System for
solving business problems is Information
System or Application Development’
• Systems are designed and implemented using
a systematic development process – Systems
Analysis & Design
7. Investigation
1) Is there a business problem?
2) Reason of problem?
3) Will new & improved Information System
solve the problem?
4) Which is most feasible Information System
solution to problem?
11. Technical Feasibility
• Suggested technology exists? Acquired?
• Recommended solution handle sufficient data
required for new solution?
• Offer responses to enquiries from number of
users from different locations
• System expandable?
• Technical guarantee for accuracy ,reliability
and security?
12. Economic Feasibility
• Cost Benefit Analysis
• Cost of hardware ,software ,license ,personnel
,office space etc vis a vis benefits
• Recovery of costs?
13. Operational Feasibility
• Can people work with new system?
• Supported by Management & Users?
• Current methods acceptable to all?
• Change impact customers?
• Change slow down performance in any area?
16. SYSTEM ANALYSIS
• What to do?
• How to do?
• Systematic investigation of real or planned
system to determine function of the system &
how they relate to each other and to any
other system
• In software development , requirement phase
is most crucial .
• User controlled stage
17. Characteristics of System Analysis
• Top Down Approach
• Use of Tools and Techniques – Functional Diagrams ,
DFDs , process specs , Entity relationships with
techniques and models
• Abstraction of Model- Creation of physical and logical
model
• Iterative Development –Improvement in analysis and
design in current step ensures improvement in
previous steps
• Advanced Technology
• Prototype
20. Phases of System Analysis
• Requirement Determination /Fact finding –
study of current system and scope of
adjustments and improvements
• Data gathering activity done during Analysis
21. Data Flow Diagram (DFD)
• Graphical representation of data flow through
an Information System is called DFD
• Used for problem understanding and Analysis
of system
• Depicts flow of data through the system
• DFD captures the transformation of input data
to produce output data
• DFD reflects movements of data through the
different transformation in the system
22. Elements of DFD
• 1.Process –Activity performed according to incoming
data flow or conditions – represented as ‘circle’ or
‘rectangle’
• 2Data Flow – Input /Output of data – represented by
‘solid line with arrow”
• 3 External Entity – Another department . A business,
person ,machine can be used to send or receive data to
and from the system . Represented by ‘square’
• 4.Data Store – Data is stored in ‘data store’ –
represented by ‘open ended box’, inventory of data
24. Levels of DFD
• 1.Context Diagram –highest level in DFD –
single process representing entire system
• 2. O Level Diagram – All process models have
only one level 0 DFD
