Planning Extreme Programming - kent beck martin fowler phần 8 ppsx

Various events cause the team to do a little release planning. The

customer adds and changes priorities of stories, developers esti￾mate 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 rela￾tively 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.

Chapter 21

Release Planning Events