1. Chapter Extension 19 Alternative Development Techniques © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke

2. CE19-2 Study Questions Why is rapid application development rapid? What is object-oriented development? What are the phases and principles of the unified process? What is extreme about extreme programming? How do development techniques compare?

3. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-3 Why Is Rapid Development Rapid? RAD – Five phases: Requirements, design, implementation, conversion,maintenance – Design/implement/fix Breaks up design and implementation phases into smaller chunks Uses computer assistance Incremental development – Requirements less detailed because users actively involved

4. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-4 Martin’s RAD Process Figure CE19-1

5. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-5 Rapid Application Design (RAD) Characteristics – Design/implement/fix development process – Continuous user involvement throughout – Extensive use of prototypes – Joint application design – Use of CASE tools

6. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-6 Prototypes Mock-up of aspect of system Vary in functionality and utility Some designed to be thrown away Help users evaluate requirements – show actual data in context – Provide opportunity for users to test interfaces – Communication device between users and developers Only a mock-up – May imply application is more complete than it actually is

7. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-7 Joint Application Design (JAD) Teams conduct design activities Incorporates feedback and testing earlier in development process Design meeting of short duration – Goal is to keep scope small – Design completed in short period

8. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-8 Computer-Assisted Software/Systems Engineering CASE tools – “Software” focuses on program development – “Systems” focuses on systems development – Uses computer systems for development – Have repository Database containing documents, data, prototypes, code – Many have code generators Programs that generate application code

9. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-9 Visual Development Tools Used in RAD projects Improve developer productivity Creates skeleton code Developers add features and functions

10. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-10 What Is Object-Oriented Development? OOD – Programs developed through object-oriented programming (OOP) Discipline for designing and writing computer programs Easier and cheaper to fix and adapt Business applications will have to integrate with non- OOP programs Unified Modeling Language – Diagramming techniques that facilitate OOP development

11. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-11 What Are the Phases and Principles of the Unified Process? UP – Designed for use with UML – Five phases Inception Similar to SDLC definition phase Elaboration Developers construct and test framework and architecture Results in working system Iterations driven by use cases Security addressed during this phase

12. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-12 Five Phases, continued Construction Developers design, implement, and test features and functions Multiple iterations Prepares system for deployment Transition Similar to SDLC conversion phase Maintenance Similar to SDLC maintenance phase

13. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-13 Phases of the Unified Process Figure CE 19-6

14. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-14 UP Principles Figure CE 19-8

15. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-15 Sears Standardizes Development Sears used a variety of different system development methodologies – Systems were inconsistent in quality and timeliness Sears created single, consistent, enterprise- wide development process – Backed by software development tools – Based on Rational Unified Process (RUP)

16. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-16 Security and Systems Development Only authorized users can take authorized actions – Decide how users will be authenticated IS authentication can be performed by operating system or network or perform own authentication – Determine users groups Permissions defined for groups instead of individuals Easier to change as a group than for each individual

17. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-17 Security and Systems Development, continued – List primary features and functions of system Direct result of systems design activity – Determine restrictions and enforcement Allow users to attempt action and issue error message Disable features and functions that user cannot perform Only display actions that users are authorized to perform – Allocate permissions to user groups Computer programs cannot provide effective controls by themselves

18. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-18 What Is Extreme About Extreme Programming? Extreme Programming (XP) – Emerging technique for developing computer programs – Used for developing application programs – Extreme iterative development Two-week development cycle Customer centric Just-in-time (JIT) design Paired programming

19. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-19 How Do Development Techniques Compare? SDLC and RAD address information systems – Used to develop organizational information systems OOD with UP and XP concerned with development of computer programs – Used by software development vendors

20. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-20 Comparison of Development Techniques Figure CE 19-9

21. © 2008 Pearson Prentice Hall, Experiencing MIS, David Kroenke CE19-21 Active Review Why is rapid application development rapid? What is object-oriented development? What are the phases and principles of the unified process? What is extreme about extreme programming? How do development techniques compare?