Tuesday, September 29, 2015

C3 - the origins of XP

I think this is not widely known, even among Scrum/XP practitioners and therefore I would like to spread it: please devote 10-15 minutes of your time to learn about C3 - Chrysler Comprehensive Compensation project.

If you read even these three short entries:

you will learn why this project is regarded as the one that gave birth to XP and you will see which, now very famous, folks from XP/Scrum world worked on C3 in the '90s.

To give you a trailer, this is what Chet Hendrickson wrote in the article that I provided the link to (last from the list). Share this with your Product Owner :-)

When C3 was restarted under Kent Beck’s coaching, Marie sat down and wrote the user stories we needed for the first release plan. She was able to explain how the stories fit together. She assigned their priority. She questioned our estimates. She would have made the estimates, if we had let her, and she would have down about as well as we did. She approved every acceptance test. She did a hundred other things that we eventually took for granted.

We don’t know how Marie learned to do all of this. Marie didn’t know how she knew it. She must have known before we started the project, because we don’t know how Marie knew these things, we were not able to help her do them. And, because Marie didn’t know, she wasn’t able to teach others how to help her (...)

Tuesday, February 3, 2015

Practical Scrum Training (7) Training Scenario

This is the final post in Practical Scrum Training. I will explain now how I imagine the training should be conducted. I imagine one day, with a lunch break, should be enough to cover what I list here below.

The training group should consist of a few (3-4) groups of individuals and there should be from 2 to maybe 4 people in each group. Each group should be seated in from of one computer.

The training begins with a description of the application and the participants should be able to run the included unit tests as well as the application itself.

Then, the trainer presents the initial product backlog.The trainer acts, to some extent, like a Product Owner. The product backlog refinement that we went through in previous posts is not meant to be performed upfront, but rather in several stages, on as-needed basis.

The goal for the teams is to build product increments in artificially short iterations - each 1 or 1.5 h long. The development team performs all regular Scrum events, like planning, review and retrospective, but because of the artificial shortening of sprints, they are not required to observe any proportion of length of these compared to the sprint itself. For the same reason, the development team does not have daily scrums.

Some of the product backlog items, like checking the validity of entered data, should be hardly possible to increment within an hour and therefore the teams will be forced to divide such product backlog items into a few smaller ones. The teams will be reminded very strongly that they must finish the product backlog items they accepted into a sprint. Leaving an item unfinished at the end of the sprint will be treated as a failure - retrospective should be used to come up with ideas how not to let it happen in next sprint.

Training attendies may choose any approach to work efficiently using one computer per each team of 2 - 4 people. They should, however, be strongly encouraged to use TDD as they code (let's state it directly: they must use TDD). More ambitious teams may try to introduce unit tests into the module that converts internal representation of the tree into pydot objects (something I did not do in the baseline of the application). Apart from wearing the Product Owner's hat the trainer should also do some duties similar to those known from sessions like code retreat: walk from group to group, provide comments and advice regarding code quality. The trainer should be able to do this craftsmanship part of the duties for smaller groups  (less groups, less people in a group).

This outline of the training and the family tree example can be used by anyone who wishes to try it out with a development team. You can use all of this information, if you want to deliver this training yourself. As the author of the training, I am also willing to deliver it in person.

See also