UserStory essence

What is Story and what is the difference between Story and Use Case? There are many discussions at present. The authoritative explanation is mentioned by Mike Cohn in "User Stories Applied: For Agile Software Development":

1. User stories are different from IEEE 830 software requirements specifications, use cases and interaction design scenarios. (User Stories are different from the software requirements specifications, Use Case and interaction design scenarios defined in IEEE830.)

2. User stories are similar to a use case scenario. ( User Stories are very similar to Use Case scenarios.)

3. user stories differ from use cases in their completeness and longevity. Use cases are much more complete than are user stories. Use cases are designed to be permanent artifacts of the development process; user stories are more transient and not intended to outlive the iteration in which they are developed. (User Stories are different from Use Cases in terms of completeness and longevity of existence. Use Cases are more complete; Use Cases are long-lived during development , while User Stories exist only temporarily within an iterative development cycle.)

4. User stories and use cases are written for different purposes. Use cases are written so that developers and customers can discuss them and agree to them. User stories are written to facilitate release planning and to serve as reminders to fill in requirements details with conversations (Writing User Stories and Use Cases also serve different purposes. Writing Use Cases is for developers to discuss and agree on requirements with customers, while Writing Use Stories is for release planning and serves as a reminder to discuss requirements details.)



Network Product line Liu Hongye also holds a similar view in "Story Essence and 9-step Method of Division", and believes that "if we make various agile practices into a string of pearls, then the Story method is the thread that pierces the pearl."



Through the above description, the meaning of Story should be clearer: the original intention of Story is not to analyze and record requirements (of course, it can be done), but to formulate an iterative development plan; a complete Use Case (module requirement) is used for coding. It is still a big deal. It is most suitable to use Stories to define various scenarios of Use Cases, such as normal processes and extended processes. However, a Use Case can be decomposed into one or more Stories and implemented in one iteration or multiple iterations. The following process of peeling a banana is a good analogy for this relationship.