How to Write an Effective Functional Use Case

I’ve been spending my days creating and analyzing business use cases for a project that I’m on. It is tedious work but it’s necessary, so the design team can go in there and create a stable and useful system.

Use cases are an analysis of a particular business process. It explains the functional step to go through a process. You shouldn’t get involved in how the system will work and how to improve it. This is just to further understand what steps users are currently going through.

Here is the look of a usual use case

1.  Use Case Title – Create a useful title for your use case

2. Use Case Description - Think of a quick and thorough description for your use case.  The first sentence should be the objective.

3. Assumptions – Write the assumptions you have before writing the use case.  For instance, “this use case does not deal with classified data.  This will be handled in another system.”

4. Actors – Who are the users for this use case.  A description should accompany each user group to describe what they are trying to get out of the process.

5. Preconditions – What has to happen before the use case can occur

6. Basic Flow of Events - What are the main steps that users have to take in order to complete the use case.

7. Alternative Flow of Events – Alternative steps that users have to take for a process with a little difference.  For example, the main steps can be to go to the bank and get cash.  The alternative flow of events can be to go to the bank and get a cashier’s check

8. Subflows - These steps are part of the basic flow of events but in more detail, if needed

9. Key Scenarios - An example of the use case.  It’s also useful to create a use case diagram, which usually looks like a flowchart with a stick figure (representing the user).

10. Postconditions - What will happen after the use case is complete? For instance, the customer will successfully get his/her cash

Optional Sections:

You can have requirements for the use case listed here as well. These can be security, nonfunctional, data, etc.

I hope this will help you take the right steps to writing a use case.

Photo Detail: The Monument Steps, originally uploaded by plbmak.