Comparison of CMM Level 2 and eXtreme Programming Copyright, 2002 © Bartosz Walter Web Applications and Services

Plan of the lecture Introduction Software Development Studio CMM Level 2 eXtreme Programming Main risk factors in CMM & XP Conclusions

Introduction Problems with the classical approach Too much paper work! Too many meetings!

Introduction XP the Deliverer We do XP from the very beginning! code + test cases Forget it! Only artefacts: IEEE/ANSI standard 830/1993? Fagan inspections? Function Points? Oral communication much more important than written one.

Introduction Heavyweight vs. lightweight  well defined process  documents drive development  stable requirements  agile process  development = testing + coding  changing requirements or

Plan of the lecture Introduction Software Development Studio CMM Level 2 eXtreme Programming Main risk factors in CMM & XP Conclusions

Software Development Studio Teaching management of software development  started in 1998  external customers  8 team members  11 project teams  1 year long  started in 1998  external customers  8 team members  11 project teams  1 year long Customer University bachelor thesis software product

Software Development Studio Software development at university? Is it a real environment? Students work part time only... How about customer participation? What is the actual goal? Is it a real environment? Students work part time only... How about customer participation? What is the actual goal? Universit y Customer

Software Development Studio SDS SDS-XPSDS-CMM 6 projects Project Areas 5 projects many documentscode & test cases reviewspair programming stable requirementschanging requirem.

Plan of the lecture Introduction Software Development Studio CMM Level 2 eXtreme Programming Main risk factors in CMM & XP Conclusions

CMM Level 2 SEI Capability Maturity Model 1. Initial 2. Repeatable 3. Defined 4. Managed 5. Optimizing Key Process Area Practice Key Process Area Practice Level 2 is project oriented!

CMM Level 2 KPAs at CMM Level 2 Requirements Management Project Planning Project Tracking and Oversight Configuration Management Quality Assurance Subcontract Management

CMM Level 2 SDS-CMM Team structure Quality Assurance (5 th year) Project Management (4 th year) Development (3 rd year)

CMM Level 2 SDS-CMM Documents Initial Project Descrip. Initial Project Plan Requirements Specif. Conceptual Design Project Plan Detailed Design Development Test report Thesis Document Draft Formal reviews (SCCB) Customer acceptance Final document (SCMB)

Introduction Projects at SDS-CMM Requirements management tool Multi-projects management A client for remote databases A tool for multiple-choice tests mgmt Elective modules assignment tool Software testing tool Requirements management tool Multi-projects management A client for remote databases A tool for multiple-choice tests mgmt Elective modules assignment tool Software testing tool CMM XP

Plan of the lecture Introduction Software Development Studio CMM Level 2 eXtreme Programming Main risk factors in CMM & XP Conclusions

eXtreme Programming Values and practices CustomerDevelopers communicatio n simplicity feedback courage XP values planning game short releases metaphor simple design test-first coding refactoring pair programming code co-ownership continouos integration no overtime on-site customer coding standard XP practices

eXtreme Programming Planning game Short releases On-site customer (part.) User stories Continuous integration Pair programming (part.) Test-first coding Coding standard Exploration We applied: Refactoring CRC cards Simple design We didn’t apply: SDS-XP process

eXtreme Programming SDS-XP Team structure Testers (5 th year) Coach & Tracker (4 th year) Development (3 rd year) Customer

eXtreme Programming SDS-XP Documents User stories Planning game Project scope Unit testing Development Accept. testing Integration

eXtreme Programming Projects at SDS-XP Requirements management tool Multi-projects management Health-care appliance system Internet client for DNA sequencing Software testing tool Requirements management tool Multi-projects management Health-care appliance system Internet client for DNA sequencing Software testing tool XP CMM XP

Plan of the lecture Introduction Software Development Studio CMM Level 2 eXtreme Programming Main risk factors in CMM & XP Conclusions

Risk factors Maintenance issues in XP How to bind user stories to test-cases and code? How to preserve system architectural design? How to understand customer needs?  difficulties in thesis completion  missing customer's business goal  poorly structured design Symptoms:  difficulties in thesis completion  missing customer's business goal  poorly structured design  business rationale for stories  metaphore + architecture  skilled students Solutions:  business rationale for stories  metaphore + architecture  skilled students

Risk factors Maintenance issues in CMM Level 2 How to keep documents consistent and up-to- date?  inconsistent documents  versioning problems Symptoms:  inconsistent documents  versioning problems  CASE tools (e.g. Rational Suite) Solutions:  CASE tools (e.g. Rational Suite)

Risk factors Customer involvement Customers underestimate their role. On-site customer is almost utopia.  customer is not available  customer cannot make desisions Symptoms:  customer is not available  customer cannot make desisions  train customers in XP  alternative communication Solutions:  train customers in XP  alternative communication

Risk factors Pair programming Some people hate pair programming. Pair-mate is not involved enough. Excessive cost of pair programming.  code contains simple mistakes  code is owned by individuals  certain people cannot work together Symptoms:  code contains simple mistakes  code is owned by individuals  certain people cannot work together  exercise pair programming  add code reviews  enforce changing partners in pairs Solutions:  exercise pair programming  add code reviews  enforce changing partners in pairs

Plan of the lecture Introduction Software Development Studio CMM Level 2 eXtreme Programming Main risk factors in CMM & XP Conclusions

SDS-CMM vs. SDS-XP SDS-CMM:  well defined process  easy to maintain  less dependent on customer  programming seems unimportant  needs a lot documentation  documents are inconsistent SDS-XP:  focused on programming  less documents to produce  stress on communication  needs experience  customer involvement is critical  problems in maintenance In students' opinion...

Conclusions More quantitative results... CRITERIONSDS-CMMSDS-XP Projects started 65 Projects completed 65 Software delivery delayed 23 Software accepted by customer 4*2 Projects continued next year 20 Software installed at customer's 22

Conclusions Sommerville-Sawyer's model Defined > 85 Basic & > 40 Interm & AdvDefined Repeatable > 55 Basic & < 40 Interm & AdvRepeatable Initial < 55 BasicInitial SDS-CMM ( ) SDS-XP (30+18)

Conclusions l SDS-XP depends on people, not on documents l SDS-CMM seems more appropriate for inexperienced developers l SDS-XP requires constant customer involvement l SDS-XP and SDS-CMM both suffer from maintenance problems (though XP is more error-prone) l SDS-CMM requires better CASE support l SDS-XP needs more management involvement