# XP
## Principle

* simplicity

* communication

* feedbck

* courage

## Core Practices

* Whole Team 

* Planning Game 

* Small Releases 

* Customer Tests

* Simple Design 

* Pair Programming

* Test-Driven Development 

* Design Improvement

* Continuous Integration 

* Collective Code Ownership 

* Coding Standard

* Metaphor 

* Sustainable Pace 

## Planning

* User stories are written

* Release planning creates the schedule

* Make frequent small releases

* The Project Velocity is measured

* The project is divided into iterations

* Iteration planning starts each iteration

* Move people around

* A stand-up meeting starts each day

* Fix XP when it breaks

## Designing

* Simplicity

* Choose a system metaphor

* Use CRC cards for design sessions 在设计会议上使用CRC卡

* Create spike solutions to reduce risk 创建穿刺方案以降低风险

* No functionality is added early 没有过早加入现在还不需要的功能

* Refactor whenever and wherever possible 只要有可能就要重构

## Coding

* The customer is always available

* Code must be written to agreed standards

* Code the unit test first

* All code is pair programmed

* Only one pair integrates code at a time

* Integrate often.

* Use collective code ownership

* Leave optimization till last

* No overtime

## Testing

* All code must have unit tests.

* All code must pass all unit tests before it can be released.

* When a bug is found tests are created

* Acceptance tests are run often and the score is published