Analyzing requirements

In Chapter 1, The Requirements Domain, we talked about the concept of the requirements funnel. This is a mental model that illustrates how requirements keep coming at us from many directions and in many forms and shapes. We need to filter these requirements and convert them to quantifiable and knowable entities so that we can process them. These items are our requirement domain entities (goals, stakeholders, capabilities, and features). If you've done chemistry at school, you may have used a separating funnel. These funnels are used to separate mixed liquids, such as oil and water. To convert requirements to requirement domain entities, we must use a mental separating funnel, which will filter the mixture of incoming requirements and then identify and create the relevant domain entities. Once we've done that, we can model those entities as an impact map, that is, our requirements model.

Our funnel will consist of distinct filtering techniques. These...