The document discusses different software development processes, including Waterfall and Agile. Waterfall involves sequential development in phases without overlap or iteration, which can lead to problems if requirements change. Agile follows four values: individuals and interactions, working software, customer collaboration, and responding to change. It emphasizes iterative development, collaboration between self-organizing cross-functional teams and business people, and adapting to changing priorities. Overall, the document analyzes the advantages of Agile over Waterfall for accommodating changing requirements through continuous planning, development, integration and testing.

1. Choosing commercial software development process Uladzimir Liashkevich, © 2009

2. Development process Software engineering – systematic and disciplined approach Code & fix - hack until it works Software development methodologies Waterfall Spiral model Rational Unified Process Agile development Lean development

3. Waterfall: theory

4. Waterfall: how it works

5. Waterfall: time-to-market Safeguard – Ballistic Missile Defense System No late changes in requirements 6 years of development 5k person-years $25 bln Terminated after 133 days of operation – new missiles were faster, than anti-missile missiles

6. Waterfall: target aiming

7. Waterfall: target aiming

8. Waterfall: target aiming

9. Waterfall: cost of change

10. Waterfall: problems Planning doesn’t work Business may change faster than software is developed Changes in requirements are not easy Cost of change Progress is not clear

11. Solution Communication & Feedback Continuous Software development as social activity It is not about applying math methods

12. Agile manifesto Individuals and interactions over processes and tools Working software over comprehensive documentation Customer collaboration over contract negotiation Responding to change over following a plan

13. Agile vs Waterfall

14. Team building Feature team Sits together Common goal Motivated individuals Team building is hard

15. Involve customer Product owner Daily collaboration Product backlog User stories Prototyping Prioritizing backlog

16. Iterative development Working software is the measure of success Continuously deliver value Early and often Valuable feedback Iteration planning High priority user stories Story estimates Acceptance criteria Iteration scope Implementation Tough things first Technical tasks as a part of user stories Complete features Continuous communication

17. Typical Agile life-cycle

18. Agile: target aiming

19. Agile: target aiming

20. Agile: target aiming

21. Quality Quality is free Only if you are ready to pay for it External quality Zero defect principle Internal quality Technological debt

22. Questions?