Balancing Agility and Discipline Chapter 4 Sharon Beall EECS 811 April 22, 2004

2 Agenda  Lease Management Example  Command Center Processing and Display System Replacement (CCPDS- R) Example  Home Ground Charts  Summary

3 Lease Management The Project  Leasing industry  500 KLOC  30 developers  20 participants  1,000 story cards  18 months with traditional approach  36 months with XP

4 Lease Management Eight “Bad Smells” 1.Time to develop story card increased in later iterations  Iteration length static  Too much tacit knowledge required  Stories subdivided to meet schedules

5 Lease Management Eight “Bad Smells” 2.Integrating functions problematic in later iterations  Individual tests okay  Failed integration with other functions  High-level architectural plan developed

6 Lease Management Eight “Bad Smells” 3.Unit and system testing issues  Tacit knowledge strain again  Complex specialized functions  Breaking tests, architecture  High-level architectural plan assisted

7 Lease Management Eight “Bad Smells” 4.Customer complaints  No complaints until later iterations  Customer never understood real user needs  Early coaching necessary

8 Lease Management Eight “Bad Smells” 5.Integration, Schedules, and Effort  Misrepresented accomplishments  Story cards taking extra effort than portrayed  Created task list for each story  Monitored by management

9 Lease Management Eight “Bad Smells” 6.Refactoring Never Done  Developers knew refactoring was needed  Busy doing assigned work  Detailed work plans and task lists included refactoring

10 Lease Management Eight “Bad Smells” 7.Simple design and YAGNI drawbacks  Developers continuously refactoring some modules  High costs since future changes known for those modules  Adopted a pattern for this module after some time (YAGNI – You Aren’t Going to Need It)

11 Lease Management Eight “Bad Smells” 8.Test drivers and re-use  Normally simple design and YAGNI  Due to size and number of objects, different tests with similar drivers for different object states  Adopted a pattern for test drivers as well

12 Lease Management Lessons Learned  Tacit knowledge is agile, however with large software projects, presents scaling problems  To diverge from an agile process requires talented people to recognize and respond  Simple design is risky on large projects with known change

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14 Lease Management Extending XP  High level architectural plans  Definitions of milestones and completion criteria  Usage of patterns and architectural solutions Authors note…scale agile processes as-needed and as-discovered!

15 CCPDS-R The Project  Re-engineer command center for missile warning system  1 million lines of code  75 programmers  3 user sets  48 months

16 CCPDS-R Agile Manifesto Individuals and Interactions over Processes and Tools TRW versus DoD  DoD milestone standards redefined to reflect stakeholder’s interest. Use of automated tools to verify software to specs.  Contract award fees designated for personnel  System architecture organized for developers’ skill levels

17 CCPDS-R Agile Manifesto Working Software over Comprehensive Documentation  DoD requires Preliminary Design Review (PDR) with docs and charts  TRW chose to put it off until software could be demonstrated  Documentation generated for those who really really needed it

18 CCPDS-R Agile Manifesto Customer Collaboration over Contract Negotiation  Win-win idea used to negotiate contracts  Ada version of COCOMO used  Allowed for savings via reuse (if Agile, would have been costs due to YAGNI and rework)

19 CCPDS-R Agile Manifesto Responding to Change over Following a Plan  Plans and specs were machine processable  Metrics tracked progress in identifying problems  Allowed easy tracking and early fixes  Easy adaptation of plans  Advance work in software reuse amongst 3 customer sets

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21 CCPDS-R Extending Plan-Driven Methods  A win-win customer driven view can be combined with a process-document driven view  Award fees generated for TRW developers

22 Summary  Examples that hybrids can succeed  Easily tailoring the process not published  Taking parts of each method to complement a given project is not easy, but can be successful  …Guidelines in the next chapter to do this!

23 Closing Questions? Comments?