Extreme Programming Modified: Embrace Requirements Engineering Practices

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Extreme Programming ModifiedEmbrace
Requirements Engineering Practices
IEEE Joint International Conference
on Requirements Engineering 9-13 September 2002,
Essen, Germany

• J. Nawrocki, M. Jasinski, B. Walter,
  A.Wojciechowski
• Poznan University of Technology, Poznan, Poland

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Introduction
"XP is the most important movement in our field
today."
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Introduction

• Interesting practices of XP
• strong customer orientation
• increments short releases
• test-first coding
• planning game etc.

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Introduction

• Weaknesses of XP
• lack of documentation
• one (on-site) customer
• too short planning perspective

How to solve those problems and preserve
agility?
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Contents
1. Introduction 2. Reconciling XP with
documentation 3. Multiple customer
representatives 4. Modifying the XP lifecycle 5.
Early evaluation results 6. Conclusions
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Reconciling XP with documentation
Travel light.
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Reconciling XP with documentation
Travel light. What you need is just code and test
cases.
IEEE Standard 830
UML
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Reconciling XP with documentation
Travel light. What you need is just code and test
cases.
Oral communication is preferred as the written
and e-mail communications (..) are error-prone.
But people sometimes forget!
Why did I decide to ..
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Reconciling XP with documentation
To be agile does not mean that you have to throw
away the (requirements) documentation.
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Reconciling XP with documentation
To be agile does not mean that you have to throw
away the (requirements) documentation.
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Reconciling XP with documentation
To be agile does not mean that you have to throw
away the requirements documentation.
In XP tester is responsible for helping the
customer choose and write functional tests. --
Kent Beck

• XP roles
• Customer
• Developer
• Coach
• Tracker
• Tester

Tester-analyst (product manager)
is responsible for writing and managing usage
scenarios, requirements, and acceptance tests.
Tools Rational RequisitePro, Rational Robot,
xUnit
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Contents
1. Introduction 2. Reconciling XP with
documentation 3. Multiple customer
representatives 4. Modifying the XP lifecycle 5.
Early evaluation results 6. Conclusions
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Weaknesses of XP
One on-site customer
If there are many it is assumed they speak one
voice.
Sometimes they dont.
We need a new car.
No! We need a new furniture.
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Multiple customer representatives
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Multiple customer representatives
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Multiple customer representatives
20 hours for you ..
Customers
6 h
9 h
More func.
More colors
How to choose the scope?
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Contents
1. Introduction 2. Reconciling XP with
documentation 3. Multiple customer
representatives 4. Modifying the XP lifecycle 5.
Early evaluation results 6. Conclusions
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Modifying the XP Lifecycle
Design for today, not for tomorrow.
Short planning perspective (one release)
One release is sometimes not enough.
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Modifying the XP Lifecycle
Design for today, not for tomorrow.
Short planning perspective (one release)
One release is sometimes not enough.
Technical risk
Utility
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Modifying the XP Lifecycle
0. Initial Project Statement (subject,
stakeholders etc.) 1. Usage scenarios (problems
visions) 2. Requirements specification 3. Project
presentation selection of developers 4. Project
planning (and risk exploration)
5. Release 1 (2 iterations, each takes 3
weeks) 6. Release 2 (2 iterations)
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Contents
1. Introduction 2. Reconciling XP with
documentation 3. Multiple customer
representatives 4. Modifying the XP lifecycle 5.
Early evaluation results 6. Conclusions
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Software Development Studio A team structure
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Experiment at PUT
Software Development Studio 2000/01
CMM Level 2
eXtremme Programming
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Experiment at PUT
Software Development Studio 2001/02
Modified eXtremme Programming
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Sommerville-Sawyer Model
RE Practices

• Interm.
• ...
• ...

• Advanced
• ...
• ...

• Basic
• ...
• ...

Defined gt 85 Basic gt 40 Interm. Adv.
Repeatable gt 55 Basic
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Sommerville-Sawyer Model
Basic IntAdv
TJam 69 31
Harpo 71 32
Predictor 70 30
Kex 68 35
EdTool 71 27
ASM 64 29
Defined gt 85 Basic gt 40 Interm. Adv.
Repeatable gt 55 Basic
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Summary

• Tester-analyst is responsible for documenting and
  managing requirements.
• Modified Planning Game tries to solve conflicts
  between multiple customers.
• Modified life-cycle emphasises requirements
  engineering and risk management.
• There is a need for user training.
• Early results are promising.

At last!
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Questions?
?