Phản hồi (Feedback): Phản hồi sớm và liên tục từ khách hàng cũng như từ nhóm phát triển giúp cho dự án luôn đi theo đúng hướng. XP đều đặn giao sản phẩm cho khách hàng để kiểm tra, theo đó khách hàng có thể 'làm mịn' và hoàn thiện yêu cầu sản phẩm dựa trên các kết quả cụ thể. Với sự trợ giúp của khách hàng, XP xây dựng một tập các phép thử phụ vụ cho việc kiểm định (acceptation test) một cách liên tục trong suốt quá trình phát triển phần mềm. | Chapter 21 Release Planning Events Various events cause the team to do a little release planning. The customer adds and changes priorities of stories developers estimate stories and team notices if it has too much or too little to do. As you are doing release planning you ll find there are several things you need to do. In this chapter we talk about the various events in release planning and how you react to them. Measuring Velocity You can think of each iteration as a box each of which can hold a limited number of wine bottles. The key question to any oenophile is how many bottles can you fit in a box You could measure the box measure the bottles and do some geometric analysis you could form a committee of august persons or you could just try it and see. We like the latter approach. At the end of each iteration we measure how much stuff got done. We assume that on average we ll get the same amount of stuff done next time. Life being what it is the amount of stuff will change from iteration to iteration but we should see a relatively steady number over time. Counting stories is not quite so easy as counting wine bottles as not all stories are of the same size. So we have to measure the size of each story. At the end of each iteration we look at all the stories that got done and we record how many weeks of ideal time it took to do each story. We then add up all the ideal time in all the stories and that tells us how much ideal time there is in each iteration. Following this simple rule violates one of the dictums of project management Work expands to fill the available space. The project manager on one of Kent s projects recently allowed as to how this just wasn t true since the team had delivered 37 days worth of stories after having initially committed to 23 and done it with two people sick the entire time. Changing the Priorities of Stories Businesses often change their priorities. By only committing to one iteration s worth of stories at a time the customer is .
