Use Case Templates

About

This is a quick summary of how to write use cases.

Advice



1. The name should start with a strong verb.
2. A use case is a set of scenarios. A scenario is a list of steps.
3. Each step should state what the user does and/or what the system responds.
   The steps must not mention how the system does something.
4. Each step needs to be analysed in detail before it becomes code.
5. Keep It Simple: use the simplest format you need.
6. Make sure you store use cases so that they are easily found, edited, and used.
7. Put use cases on a project web site.
8. Keep track of different versions.
9. Writing use cases is a team sport.
10. Focus on a particular user (give them a name).
11. Don't get bogged down in all the special ways it can go wrong until you've finished the main success story.



Start with a meaningful name

The minimum documentation is a well chosen name. It should start with a verb and indicate the type of user, and what they achieve:

 		Enrol student in class.

This is better than nothing... and the start for drafting more complete descriptions of the use case.

Brief Format

Name + Terse one paragraph description of who does what to get what.

 		Enrol student in class

---

The student logs in to the enrolment system and requests a list of sections of a class. They then select one class to enrol in and the system records this enrolment. The student is provided with confirmation that they have been enrolled.

---

Casual Format

Name
(Main Success Scenario): one paragraph.
(Alternate scenario 1): if ...., one paragraph
(Alternate scenario 2): if ...., one paragraph

. . . . . . . . . ( end of section Casual Format) <<Contents | End>>

Fully Dressed

Here are the headings for a fully dressed use case

Name

Start with a verb, numbering optional

Scope

The System Under Design or Context

Level

Enterpise goal, User-goal, or subfunction

Primary Actor

Name the actor who uses the system under design to achieve some goal.

Stakeholders and Interests

• (stakeholder1): what they want.
• (stockholder2): what they want.

Preconditions

State what special and interesting things must be true for this particular case to work.

Postconditions

List the interesting things that are true after a scenario is completed.

Main Success Scenario

1. step_number: actor does something or system responds

   Extensions

   
   (steps letter): condition
   
   1. actor does something/system does something
   
   

   . . . . . . . . . ( end of section Extensions) <<Contents | End>>

   Special Requirements

   • desired quality or technological limitation

   Variations in Technology and Data

   • step number: possible change in technology or data format

   Frequency of Occurrence

   Miscellaneous

   • Question
   • Topic to research

   Fully dressed as a table

   Here is a Tabular Format

   Name	Start with a verb, numbering optional
   Scope	The System under Design
   Level	User-goal or subfunction
   Primary Actor	Asks the SUD to deliver service to meet goals
   Stakeholders and Interests	(stakeholder1): what they want.
   Preconditions	State what special and interesting things must be true for this particular case to work.
   Postconditions	List the interesting things that are true after a scenario is completed
   Main Success Scenario	actor does something or system responds
   Extensions	(steps letter): condition steps
   Special Requirements	desired qualities or technological limitations
   Variations in Technology and Data	step number: possible change in technology or data format
   Frequency of Occurrence	How often
   Miscellaneous	Open issues to research

. . . . . . . . . ( end of section Fully Dressed) <<Contents | End>>

. . . . . . . . . ( end of section Use Case Templates) <<Contents | End>>