Chapter 16: Trends in System Development

1. Chapter 16:Trends in System Development Systems Analysis and Design in a Changing World

2. Reasons for Slow Development • Rework • Using the wrong software • Not meeting minimum quality standards • Shifting requirements and project changes • Changes to design and construction • Improper tools and techniques for project • Reduces quality, increases development time • Poor Project Management Systems Analysis and Design in a Changing World, 3rd Edition

3. Cost of Change in Each Project Phase Systems Analysis and Design in a Changing World, 3rd Edition

4. What is RAD? • Collection of development approaches, techniques, tools, and technologies • RAD proven to shorten development schedules • No universal RAD approach shortens every project schedule • No technique, tools or technology fits perfectly • Key is identifying overall development approach and matching set of techniques, tools, techniques most suitable to approach and specific project Systems Analysis and Design in a Changing World, 3rd Edition

5. Rapid Application Development • RAD is overused and poorly understood • Software developers claim they do, but cannot precisely define • Equated with tools and techniques • Prototyping, fourth-generation programming languages, CASE tools • Object-oriented analysis, design, and development • Tool vendors and methodologies claim RAD • Competing and confusing claims Systems Analysis and Design in a Changing World, 3rd Edition

6. Development Approach as a Function of Project Characteristics Systems Analysis and Design in a Changing World, 3rd Edition

7. Prototyping Approach to Development • Discovery prototype • Used in analysis or early design • Uncover or refine system requirements • Can be thrown away • Developmental prototype • Not thrown away • Part of iterative development until final system complete Systems Analysis and Design in a Changing World, 3rd Edition

8. When to Use a Prototyping Approach • When to use: • Requirements cannot be fully specified outside of architectural or detailed design • Technical feasibility unknown or uncertain • Development tools powerful enough to create functional system • When not to use: • System is non-interactive or internally complex • Strict security or performance requirements exist Systems Analysis and Design in a Changing World, 3rd Edition

9. Prototyping Tool Requirements • Development speed • Flexibility and power • Techniques and capabilities • WYSIWYG (what you see is what you get) • Generation of complete programs, program skeletons, or database schemas from diagrams • Rapid customization of software libraries or components • Error-checking and debugging capabilities Systems Analysis and Design in a Changing World, 3rd Edition

10. Prototyping Tools • Simple • Access • Excel • Graphical • Visual Studio .NET • PowerBuilder • Oracle Forms Systems Analysis and Design in a Changing World, 3rd Edition

11. Prototyping FPF Principle • Make it Functional • Make it Pretty • Make it Fast Systems Analysis and Design in a Changing World, 3rd Edition

12. Spiral Approach to Development • Iterative development approach • Each iteration may include combination of planning, analysis, design, or development steps • More radical departure from traditional development than prototyping development Systems Analysis and Design in a Changing World, 3rd Edition

13. The Spiral Life Cycle Systems Analysis and Design in a Changing World, 3rd Edition

14. Steps in the Spiral Development Approach • Criteria for feature selection for each prototype • User priorities • Uncertain requirements • Function reuse • Implementation risk • Break into categories • “Must have”, “Should have”, “Nice to have” • Complete high priorities earlier to reduce risk Systems Analysis and Design in a Changing World, 3rd Edition

15. Benefits and Risks of Spiral Development • Benefits • High parallelism • High user involvement • Gradual resource commitment • Frequent product delivery • Risks • Management difficulties and design complexity • More potential for rework Systems Analysis and Design in a Changing World, 3rd Edition

16. Cumulative Cost Plotted Against Time Systems Analysis and Design in a Changing World, 3rd Edition

17. The Unified Process • Comprehensive development approach • Originally developed by Jacobsen, Booch, and Rumbaugh in late 1990s • Dominant approach for developing software with OO models and tools • Adopts iteration from prototyping and spiral development approaches • Exclusive reliance on OO models, tools, and techniques Systems Analysis and Design in a Changing World, 3rd Edition

18. UP Phases and Objectives (Figure 16-2) Systems Analysis and Design in a Changing World, 3rd Edition

19. The Unified Process Life Cycle (Figure 16-1) Systems Analysis and Design in a Changing World, 3rd Edition

20. When to Use the Unified Process • Benefits and risks mirror spiral development • Major obstacles to adopt UP include: • Complex project management (compared to sequential development) required • Need to adopt OO models, tools, techniques throughout project • UP’s formal steps, well-defined roles, attention to model building and validation makes UP preferred approach for large-scale development Systems Analysis and Design in a Changing World, 3rd Edition

21. Rapid Development Techniques • Collection of guidelines used to help an analyst complete system development activities or tasks • Risk management • Joint application design (JAD) • Tool-based development • Software reuse • Object frameworks Systems Analysis and Design in a Changing World, 3rd Edition

22. Components and the Development Life Cycle • Purchased components can form part or all of system • Components provide one model for designing and deploying systems • Component issues • Internally developed components • Object-oriented techniques • Designing components for reuse Systems Analysis and Design in a Changing World, 3rd Edition

23. Activities Added to SDLC Phases when Components are Purchased Systems Analysis and Design in a Changing World, 3rd Edition