Gary Hughes, South Oakleigh College

1. The SDLC and the SDC: a brief introduction Gary Hughes,South Oakleigh College For VCE Software Development ¾, 2009

2. SDLC overview • Systems development life cycle (SDLC); - Analysis. - Design. - Development. - Implementation. - Evaluation. • A process by which a systems analyst analyses and designs a new information system to suit a particular purpose

3. SDLC overview • Lots of versions exist – the only one that matters is the one in the study design • Often drawn as a ‘circle’ however, the time between cycles is often quite long • Different ways of implementing it: • Waterfall model • Agile model

4. Waterfall model • Classic version of the SDLC • In practice, not practical • No feedback or iterative processes • Each stage is carried out to completion before moving to the next • That is, once analysis is done, design stage begins and so on • What if the client wishes to make changes or adjustments after the design phase has passed?

5. Agile model • Practical version, often used. • Works on smaller iterations of the SDLC. • Involves more interaction with the users of the system. • Feedback gathered at the conclusion of each stage. • May result in stage being performed again or moving up the cycle instead of down. • Takes longer, but with better results.

6. SDLC: Analysis • SDLC: Analysis; • Preliminary investigation, reasons for change. • Feasibility study: is it worth fixing?; • Collect data: measure, count, survey, interview, observe, research, test, study. • Processes. • What is the problem? • Assumptions. • Scope.

7. SDLC: Design • SDLC: Design; • Logical design & physical design. • Alternative solutions? • Data structures, input, output, processing required, validation rules, storage requirements. • Interfaces. • Hardware, software needs. • Backup, security requirements. • Employee needs, requirements. • Assessing alternative design solutions

8. SDLC: Development, Implementation and Evaluation • SDLC: Development, Implementation, Evaluation; • Development. • Components are purchased. • Software is written (if necessary). • System is assembled. • Implementation. • Putting the new system in place. • Training. • Evaluation. • Solves stated problems?

9. SDC • Software Development Cycle (SDC); • Occurs within development stage of SDLC. • Stages: • Analysis. • Design. • Development. • Testing. • Documentation. • Evaluation.

10. SDC: Analysis • Software Development Cycle (SDC): Analysis • Defining the problem. • Requirements, scope, available resources. • Project plan, time frame, programmers assigned to particular parts of the project. • Choice of programming language. • Compiled / interpreted. • Low-level, high-level. • Object-orientated (OO). • Hardware factors affecting software design.

11. SDC: Design • Software Development Cycle (SDC): Design; • Method: Top-down, bottom-up, RAD, prototyping, EUD. • Algorithms: flowcharts, NS diagrams, pseudo-code. • Desk checks. • File management. • Data structures.

12. SDC: Development and Testing • Software Development Cycle (SDC): Development; • Good programming practice / conventions. • ‘Standard algorithms’. • Software Development Cycle (SDC): Testing; • Testing Tables. • Selecting test data. • Alpha testing (or white box). • Beta testing (or black box). • Quality assurance: developer testing. • Acceptance testing: client testing.

13. SDC: Documentation • Software Development Cycle (SDC): Documentation; • Types. • User guide. • Technical reference manual. • Installation manual. • Quick start guide. • Help guide, troubleshooting. • Procedures manual. • Forms. • Print, On-line, Video, Poster.