CS405 Systems Development Life Cycle

1. CS405 Systems Development Life Cycle

2. Traditional Project Phases • Wild Enthusiasm • Growing Concern • Mounting Terror • Resigned Fatalism • Persecution of the Innocent • Promotion of the Uninvolved

3. SDLC Phases • SDLC phases • Project Initiation • Requirements definition • Detail design • Construction • Integration testing • Implementation • “Methodology” • A formal statement of the purpose, products and tasks for each phase • Many software development companies have either created or adopted a methodology to ensure process consistency and system quality

4. SDLC Phases • Project initiation (5% of total effort) • Why • Determine overall desirability • Allow project to be prioritized vis-à-vis other projects • What • Project Initiation Report outlining • Value of the project • Proposed technologies • Projected cost of the project • Expected timeline • accurate +/- 100% • How • Interviews with the business • Technology evaluation

5. SDLC Phases • Requirements Definition (15% of total effort) • Why • Create a “contract” for what is to be developed • What • System Functional Requirements • A business flow showing how the users will interact with the system in performing various supported business functions • All input/output displays/reports should be defined precisely in terms of the data content at the data field level (see Data Dictionary) and the desired functionality. Exact screen/report layout is not important • A Data Dictionary defining each data field to be used on displays and reports • Detailed project plan for next phase; high-level project plan for remaining phases • Revised project cost and timeline • Should identify potential risk factors; e.g. new technology, multi-national project organization, etc. • Accurate to +/- 50%

6. SDLC Phases • How • User interviews • Technology evaluation • Walkthroughs of the proposed system • “Playscripts” • Management review and approval to procede to the next phase

7. SDLC Phases • Detail design (20% of total effort) • Why • Finalize the design of the entire system for sponsor approval and actual development • Create a basis for vendor bidding and selection • What • Final in/output displays/reports • Detail description of inputs/outputs to/from other systems • Final logical database design • High-level software specifications • Revised project cost/timeline accurate to +/- 10%

8. SDLC Phases • How • Detail display/report design • Detail interface design • Detail logical database design • High-level software design • Validation sessions with sponsors • Project planning and cost estimates • Remainder of the project phases should be planned in detail

9. SDLC Phases • Construction and Unit Testing (20% of total effort) • Why • Develop a working system • Demonstrate that individual components perform as specified. • Prepare for integration testing and implementation • What • A working database • Working software • Unit test results • Integration test plan • Implementation plan • How • Detail logic design • Coding • Unit testing

10. SDLC Phases • Integration Testing (30% of total effort) • Why • Ensure that all elements of the systems interact correctly under all circumstances • Ensure that the system will give acceptable performance under the volume of processing expected • What • A fully tested system • Completed system documentation • Authorization to proceed to implementation

11. SDLC Phases • How (a “black art”) • String testing • Scenario testing • “day-in-the-life” testing • playscripts • Parallel testing • Run an actual day and compare to what the old system produced • Very time consuming/expensive • Implementation testing • Test conversion programs, history loading programs, etc. • Performance testing

12. SDLC Phases • Implementation (10% of total effort) • Why • Implement a working system • What • “live” application • How • Hardware installation • Software installation/roll out • User training • Data conversion • Cut over • Post-implementation support (“hypercare”)