In part 1 I talked about stakeholder needs, both implicit and explicit and how these needs should be the core to any good requirement.   I also talked about the importance of correctly defining the user group from which needs will be elicited.

Once all user needs are identified and specified, it is the responsibility of the project’s business and engineering teams to understand how they can capably solve these needs.   In our restaurant example, the patron who entered the restaurant craving a sizzling stake would be wasting his time in a restaurant that only served raw food.

The requirements pyramid below shows the hierarchy of needs, features, requirements and the boundary that separates them in the problem and solution domains.

Source: http://www.ibm.com

The reference to features can better be understood as the range of options and constraints across people, process and technology that will influence the method and approach used to solve the problem.  Understanding and matching features with user needs will drive the requirement specification process.

Click here for part three to our series on Clarifying Requirements.