System Development Life Cycle
What is SDLC?
The formal process by which organizations
build systems is known as SDLC.
Also referred to as
Application Development Life Cycle or
Structured Development Life Cycle
TQM/RE
TQM-Total Quality Management
Set of business practices which improve
profit and productivity
RE- Reengineering/Process Innovation
Changing fundamental procedures
reexamining/repositioning corporate
Strategies.
TQM/RE Goals
•Improve quality of all company activities
•Reduce costs
•Improve timelines
•Other business goals
Why systems fail?
•Lack of communication between people
•Continuing the old system
•Failure of parts of system not fitting
•Lack of management Support
•Technological Incompetence
•Changes in technology in the middle
•Lack of user involvement/training/support
(missing JAD-Joint Application Development)
Why systems fail?
(Not following steps of SDLC)
•System does not meet users’ needs
•Unnecessary/insufficient hardware is acquired
•Software inadequately tested
Six Phases of SDLC
1.
2.
3.
4.
5.
6.
Preliminary Investigation
Systems Analysis
Systems Design
Systems Development/Acquision
Systems Implementation
Systems Maintenance
Person in charge: Project Leader
System Analyst/Engineer
1. Preliminary Investigation
(feasibility study)
Determine the organization’s objective
Read internal/external documents
Interview users/executives
Nature and scope of problems
Propose alternative solutions
leave the system as is
modify the existing system
develop a new system
Describe costs/benefits of each solution
Submit a preliminary plan with recommendation
1. Preliminary Investigation
Benefits
Tangible Cost savings
Profitability/Productivity
Intangible
Employer satisfaction
BPR (Business Process reengineering)
independent of IT
Processes are identified for bottlenecks,
removed, then IT is applied.
2. System Analysis
Gather data
documents, interviews, questionnaires,
observations, sampling
Analyze data
CASE tools, DFDs, Data Dictionary,
System Flowcharts, Connectivity
Diagrams, Grid Charts, Decision Tables
Write a report
Written report
Approval from the Manager
next phase
3. System Design
Preliminary Design
describes the functional capabilities
of the system
CASE tools, PM Software
Detailed Design
Output Requirements
Input Requirements
Storage Requirements
Processing/Network Requirements
System Backup
4. System Development
Substantial expenditures of money/time
Acquire software
Acquire hardware
Test the System
Unit Testing
Integrated testing
Workable system ready to be implemented
5. System Implementation
Objective:
To make system not just workable but successful
1. Software Conversion/Data conversion
4 Major strategies
Direct Implementation
Parallel Implementation
Phased Implementation
Pilot Implementation
2. Documentation
3. Training
4. System Maintenance
Never ending phase
Adjustments/improvements
system monitoring
Auditing- independent auditor’s review
Evaluation- outside system analyst
Once the system is old enough
SDLC is started all over again.