Use cases define the functional scope of a specific system actor (or role).

User stories define individual capabilities needed by a specific user actor or role.

USE CASE

A use case could be defined by multiple user stories making up a use case scenario (see below) and therefore a user story could map onto one or more use cases.

Emrah Yayici of the BA Works consultancy suggests a use case template that consists of:

• a unique ID
• a name
• a description
• a list of actors
• pre conditions
• post conditions
• a main scenario
• an alternate scenario
• an exception scenario
• the non functional requirements
• the business rules
• any assumptions made

USER STORIES

User stories are actually comprised of two parts:

1. the story
2. the acceptance criteria

The story takes the form: as a [role] I want [goal] or as a [role] I can [do something] so that [a goal can be reached]

The acceptance criteria are essential as these function to define the requirements of the 'headline' story in more detail for the developers tasked to deliver the story and to act as testing criteria for use by the deliverable owner tasked with testing the story deliverable.

Implementation 6