Friday, 21 December 2012

Limitation of Use Case

3.13 Limitations of Use Cases

Use cases alone are not sufficient. There are kinds of requirements (mostly nonfunctional) that need to be understood. Since use cases provide a user’s perspective, they describe the system as a black box and hide the internal details from the users. Hence, in a use case, domain (business) rules as well as legal issues are not documented.

The non-functional requirements are also not documented in the use cases. As examples of those, consider the following requirements.

  • Usability
    Color blind people should not have any difficulty in using the system – color coding should take care of common forms of color blindness.
  • Reliability
    The system needs to support 7 x 24 operation
  • Performance
    - Authorization should be completed within 1 minute 90% of the time.
    - Average authorization confirmation time should not exceed 30 seconds.
  • Portability
    The system should run on Windows 98 and above as well as Sun Solaris 7.0 and above.
  • Access
    System should be accessible over the internet – hidden requirement – security
Because of this shortcoming, use cases must be augmented by additional information.

The next post is very important for Software Engineering and we will discuss Source and Sink Analysis

No comments:

Post a Comment