3.7 The Role of the Prototype

A prototype is a software mock-up of a system's user interface, but no more. It helps round out the requirements picture, showing the user interface requirements clearly and, often, interactively.

In our approach, we propose moving the prototype to a later stage in the lifecycle: after the requirements have had a chance to gel. Introducing user interfaces onscreen at this later stage is less of a distraction for the users and helps you to avoid the temptation to solve problems before they are understood . This problem is discussed further in Chapter 4.

Technical prototyping is a design activity that reduces technological risk by letting the team try out the technically tough pieces of the solution before the design and build activities are properly under way. This is a great way to collapse assumptions, especially when the problems or toolkit involved is new. Prototyping performed simultaneously with requirements activities is not a part of the requirements process and is outside this book's scope.