Overview

The goal of the Requirements workflow is to engineer the requirements for your system to the 80% point the point at which you generally understand what the system is supposed to do but you still have some details that you need to research and understand. The purpose of requirements engineering is to determine what your customer actually wants, not what you think they want. The fact that you may have more than one group of customers for your system often complicates your requirements engineering efforts. For example, perhaps you have line workers that will use your system to do their daily jobs, their managers use portions of your system to facilitate their employee s efforts, and the marketing department uses sales information generated by your system. Another complication that you need to overcome is the fact that you often don t have access to your users/customers which experience often proves to be a leading cause of failure for many projects.

During the Elaboration phase, your goal is to evolve your requirements model to the 80% completion point.

There are many ways to engineer the requirements for your system, as you can see depicted by the solution for the Define and Validate Initial Requirements process pattern (Ambler, 1998b) of Figure 4.1 (the techniques of which are described in section 4.4.1 Engineering Object-Oriented Requirements of this chapter). An important point to note is that there are many requirements engineering techniques; use case modeling is...