Đơn giản (Simplicity): XP đảm bảo chỉ phát triển những chức năng mà khách hàng yêu cầu. Phần thiết kế và mã nguồn được thiết lập một cách đơn giản nhất, cho phép có được đặc tính 'mở' cao nhằm đáp ứng với các thay đổi liên tục và luôn duy trì được một tốc độ phát triển nhanh trong suốt quá trình phát triển phần mềm | A deferred story goes on the list for the next iteration and you will consider it again at that time unless the release plan has been adjusted in the meantime. You may be tempted to adjust the release plan if you defer a story. You don t have to rush to that. Often you can go for an iteration or two before the snowplow effect becomes so great that you need to rework the release plan. Often the deferments are too small to be an issue right away and they need to mount up before it s worth trying to deal with them. Too Little To Do Go ahead laugh but it does happen from time to time. This process is the reverse of too much to do. The developers ask the customer is to add some work. The customer can add a whole story or split a story and move a part in. However as usual the customer decides what gets moved not the developers. 132 Example Iteration Plan We ll dig some more stuff out of the time capsule to show the iteration plan for the second iteration. The notes look like this Lowest Fare Alternative fare finder object - KB 2 Find candidate fares by date range - MF 1 Update planet ports to find alternatives - KB 1 Find candidate fares for alternative ports - KB 1 Special offers - major space lines - MF 2 Special offers - low price space lines - RJ 3 UI for low fares - RJ 1 Review Itinerary Simple UI display of itineraries - WC 2 Display detail for one itinerary - RJ 2 Book Hotel Hotel Booking interfacer - MF 1 Interface to IHAB - MF 2 Interface to HiHat - MF 1 Interface to Mary s Rote - MF 1 Interface to HillTown - WC 1 Interface to Best Southern - RJ 1 Interface to Woodstar - WC 1 Show Hotels - IHAB by city Query IHAB for hotels for named city - WC 2 UI for named city display - WC 1 Other UI Clean up - KA 2 Network Performance Improvement - KB 2 Investigate using IPv84 - KB 1 Here s some points to note. Notice that the tasks in the stories don t necessarily add up to the estimates in the release plan. Book Hotel was marked as 1 ideal 133 week but comes out as 8 ideal
