The main purpose with use cases is to document and prioritize the system requirements independent of platform and specific implementation. Throughout the entire development process use cases can ensure that requirements are implemented as scoped and they may also be used for reporting progress in the project to the customers.
At Sirius IT we operate with three levels of description in a use case:
Strategic use cases are used for providing an overview of a work process. The strategic use cases are described in connection with the appropriate system and business process. They will be prioritized according to their level of impact on the final system.
Use cases on the user level are used to describe the individual user tasks in a given process. These are the most important use cases in the analysis. Most use case will depend on the technologies/tools that are available to the user.
Use cases on the system level are used to describe specific system related tasks.
Most common use cases are developed on the user level – this level describes the individual user tasks in any given process.
Based on use cases we create a matrix to prioritize the use cases. The matrix is used as part of the final description of the solution in addition to the use case descriptions.
The use cases can serve as input when developing prototypes of the user interface, ‘swimlanes’ documenting the work process, developing test cases and writing up a test specification early in the project.