Thursday, October 22, 2009

SCRUM User Stories

In Scrum, work is expressed in the backlog as user stories. A team may write its user stories in a number of ways as long as they are written from the perspective of the end user. Put another way, team members are encouraged to think of their work from the perspective of who will use it (hence “user” story). A team can express a story as a noun (i.e. “text message” on a cell phone project) or a sentence or phrase (i.e. “debug GPS tracking system”).

Many Scrum teams have adopted the user story template developed by Mike Cohn, which identifies who the end user is, what the end user wants, and why in a single sentence. This model of the user story is most often written like this: “As a [end user role], I want [the desire] so that [the rationale]."

To illustrate, consider how a developer working on a calculator application for a PC might express his work. First, the developer would want to identify who will benefit from this appication: a PC user. Second, he would want to decide what the PC user will want to get out of it: a convenient, prepackaged calculator application. Third, he would want to be able to explain why it’s important for the PC user to have this application. This piece of information is the most open to interpretation, but one can safely assume that the PC user would want to use it to add, subtract, multiply, and divide. Thus the developer’s user story could read something like the following: “As a PC user, I want a calculator with basic functionality on my PC so that I can conveniently perform basic mathematic operations.”

In summary, user stories document requirements with particular attention to the end user’s point of view. Stories can be written in myriad ways, but Cohn’s model really works in Scrum because it provides so much information about the story. Because user stories are oriented to reflect the desires of the end user, they help developers remain focused on the customer.

Daqui: http://scrummethodology.com/scrum-user-stories/

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