PROXY REQUIREMENT EXAMPLES

See definition of proxy. For example:

1.0 The system shall be user-friendly.
2.0 The user interface shall indicate the correct format for data input.

Discussion: Although 2.0 is shown at the same level as 1.0 above, it is a proxy for user-friendly. Changing the organization corrects the problem. (Note: the meaning of "user friendly" depends on the user and the business they are in, which is why proxies must be identified.)

1.0 The system shall be user-friendly.
     1.1 The user interface shall indicate the correct format for data input.

Example:

The system shall be flexible.

Discussion: The requirement is OK as a parent requirement. It needs proxies because it is not independent, testable, or able to be decomposed. System-level requirements specifying qualities such as flexibility may need standards as their proxies.

A standard that promotes simple, well-documented, modular software should address this problem requirement. Generally, software that can be modified to work in different environments is considered flexible.