System Development Life Cycle What is SDLC The

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.