ABSTRACT
Our goal in this chapter is to explain in full detail the first of the five phases of CWA. The
concept of work domain analysis, introduced in chapter 3, is probably the most important
and unique phase of CWA. We begin by discussing the nature of field descriptions to give
you an appreciation for why work domain analysis is so important. Then, we describe
Rasmussen’s (1979b, 1985) abstraction-decomposition space, a two-dimensional
modeling tool that can be used to build work domain models (cf. Fig. 5.8). The
characteristics and advantages of one dimension in this space, the abstraction hierarchy
(AH), are then described in more detail because the AH is more difficult to understand
than the decomposition hierarchy. Next, examples of how the abstraction-decomposition
space can be used to conduct a work domain analysis are presented for the case study
introduced in chapter 6. By the end of this chapter, you should understand why work
domain analysis identifies a fundamental set of constraints on the actions of any actor,
thereby providing a solid foundation for subsequent phases of CWA.
