XP Explained

Chapters 7-9

Primary Practices

Sit together Ideal Resistance Multi-site

Whole Team All the necessary skills in a single

management structure This is dynamic No fractional staff

Primary Practices

Informative workspace Key metrics as big graphs and charts Visible planning and tracking Requirements groups

Energized Work 40 hour week Focus time

Primary Practices

Pair Programming (switch as needed, maybe multiple times per day) Keep each other on task Brainstorm Clarify Switch lead when one is stuck Hold each accountable

Primary Practices

Pair Programming and personal space See figure 6 page 44 We like our personal space!

Primary Practices

Stories Plan using units of customer visible

functionality Provide a 2 click way for customers to dial

frequently used numbers Make technical requirements visible with

test cases Requirement is a misnomer Value cannot be determined with out

cost estimates

Primary Practices

Weekly Cycle Weekly meeting

Review progress Customer pick new weeks worth of stories Break stories into tasks, team members

sign up for tasks and estimate them Start the week by writing automated

test

Primary Practices

Quarterly Cycle Reflect on the team, project, progress. Process,

and alignment with larger goals Quarterly meeting

Identify bottlenecks Initiate repairs Plan themes Big picture – where the project fits within

stakeholder concerns

Primary Practices

Slack Everything can’t be planned Include tasks in the plan that could be

dropped

Primary Practices

Ten Minute Build Automatically build and test in 10

minutes. What if you can’t

You can more often that you think

Primary Practices

Continuous integration Integrate and test changes after no

more than a couple of hours Integration can take more time that the

original programming Synchronous is better than

Asynchronous

Primary Practices

Test first Programming Write the tests before the code –and do

it at a very fine level of granularity. If it is hard to write a test you have a

design problem not a test problem Rhythm

Primary Practices

Incremental Design Invest in the design of the system

every day Defer design decisions to the last

responsible moment The most effective time to design is in

the light of experience The closer the implementation of a

design mechanism to the time it is actually needed, the more efficient

Chapter 8

Getting Started

Getting Started

Make adopting XP an XP project Write stories

Educate management Attending training Automate the build

Prioritize the stories Estimate their time and cost Create and track metrics

Chapter 9

Corollary Practices

Corollary Practices

Real Customer Involvement Make your stakeholders part of the

team

Corollary Practices

Incremental Deployment Run parallel systems if necessary

Corollary Practices

Team Continuity Don’t throw everyone back into the

“labor pool” once a project is finished

Corollary Practices

Shrinking Teams As a team grows in capability, keep its

workload constant but gradually reduce its size

Corollary Practices

Root Cause Analysis When you find a defect, eliminate the

defect and the cause The goal is that the team won’t ever

make the same mistake again I expect that individuals will make

mistakes, but my process should ensure that my team doesn’t make mistakes

Five whys

Corollary Practices

Shared Code Anyone can improve any part of the

system at anytime Eliminates bottlenecks Doesn’t work across team boundries

Corollary Practices

Code and Tests Maintain only the code and tests as

permanent artifacts. Generate other documents from the code and tests. Rely on Social mechanisms for the rest.

Corollary Practices

Single Code Base Duplication is not fun and it is very

expensive Frameworks can help solve this

Corollary Practices

Daily Deployment Put new software into production every

night

Corollary Practices

Negotiated Scope Contract Write contracts that fix time, costs, and

quality but call for an ongoing negotiation of the scope

Fix scope but leave specific requirement to ongoing negotiation

Sign a series of shorter contracts rather than one big one