Planning Extreme Programming - kent beck martin fowler phần 9 docx

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A deferred story goes on the list for the next iteration and you will con￾sider 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.

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Example Iteration Plan

We’ll dig some more stuff out of the time capsule to show the itera￾tion 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

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week but comes out as 8 ideal days. Lowest Fare was 3 ideal weeks

but came out as 11 ideal days. This is quite usual as you start esti￾mating in more detail and have more information about the itera￾tion. In this case they cancel out pretty well, but of course they

often don’t.

✧ Since there is time left over the team took a part of the Show

Hotels story and built a little bit of that. Here the customer split

the Show Hotels story to get a piece that was useful yet enough

for the team to use up the extra time they had available.

✧ Most of the team have a velocity of 7, however KA has a velocity

of 2. This maybe because he’s part time, or new to the team, or

just estimates differently.

✧ There are plenty of dependencies in the tasks, but the plan doesn’t

note any of them. From watching the videos we could tell that the

alternative fare finder object was needed before you could find

candidate fares by date range or find candidate fares for alternative

ports. Also you need to do the update of planet ports to show

alternatives before you can find candidates for alternative ports.

None of this is on the plan, since this is an XP team we can safely

assume that MF and KB are intelligent beings who will communi￾cate about the order things need to be done and will sort things

out between them.