Use Cases and Nonfunctional Requirements


A product use case represents an amount of work the product does when the work is responding to a business event. In earlier chapters, you saw how the scenario breaks the product use case into a number of steps; for each of these steps, you can determine the functional requirements. The nonfunctional requirements, however, do not fit so neatly into this partitioning theme. Some of them can be linked directly to a functional requirement, some apply to the use case as a whole, and some apply to the entire product. Figure 8.2 shows this linking between the functionality and the associated nonfunctional requirements.

Figure 8.2.

Nonfunctional requirements are properties the functionality must have. The functionality can be represented either by a use case or by a functional requirement. In this example, the use case has three functional requirements, each having some nonfunctional properties. The use case as a whole must meet certain usability requirements, whereas the look and feel requirements relate to the entire product.





Mastering the Requirements Process
Mastering the Requirements Process (2nd Edition)
ISBN: 0321419499
EAN: 2147483647
Year: 2006
Pages: 371

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