Re: Practice: Stories

Kent Beck wrote:
> Give stories short names in addition to a short prose or graphical
> description. Write the stories on index cards and put them on a
> frequently-passed wall. Figure 6 is a sample card of a story I wish my
> scanner program implemented.

When I started with XP 5 years ago, I immediately bumped into formal
requiements, as well as real need, for traceability of
user stories, engineering tasks, and acceptance tests.

(Traceability of requirements throughout the development cycle is especially
important if you do medical or other safety-critical development.)

I solved this in my first XP-team with a simple practice hat I learned from
my accountant when I first started my own business in 1982.

"Mark each proof of expense or income with a unique number.
Start at 1 and count up.
Start over each fiscal year."

I teach my teams to

* Mark each User Story with US and a number. Eg US1, US2, etc

* Mark each Acceptance Test  with an AT and a number, eg AT1, AT2, etc
   Mark also each Acceptance Test with a short form reference to the user
story it verifies, eg US52.

* Mark each Engineering Task with an ET and a number, eg ET1, ET2, etc
   Mark also each Engineering Task with a short form reference to the user
story it contributes to, eg US52.

The teams maintain a single card with three numbers on it: The last used
number for each of US, ET and AT.
This card is kept with the other cards, usually on a wall with adhesive
boards.

We mark cards immediately when we create them, not when we prioritize and
plan with them.
This means that there is usually little or no correspondance between actual
priority and the reference numbers.

We backup the iteration plan with still images of our wall.

Some teams plan at the wall, some teams take down the adhesive boards and go
and plan in a meeting room, every forthnight.
---

I know that Mike Cohn, author of the excellent book "User Stories Applied"
recommed us avoiding numbers on stories in favor of good titles.

I say do both.

Mike sees a risk that people do not think enough about what a story means,
and that the numbers imply an order of priority.

I agree with the value of having strong titles on each user story, since it
helps the team to think of what they actually build.
Much like Dave Wests discussion of object names in his recent book "Object
Thinking"
But I find that the short form references, as outlined above, adds value as
well.

The practice of short form references actually fulfills even the strongest
formal requirements for traceability if the team add the US#/AT#/ET#
references in their checkin comments in the version control.


Most heavy process and tool pedlars say that you need a lot of processes and
tools to achieve traceability.

The truth: You just need references that you can trace.

/Erik

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