ABSTRACT
OVERVIEW In creating a work domain model of a system, it is useful for analysts to think about the number, types, and labels of the levels of abstraction that should be included in the model. This chapter reviews representations of a range of systems to establish whether a widely accepted set of levels of abstraction, that described by Rasmussen (1986) and Rasmussen et al. (1994), can be confidently adopted for modeling any system or whether it may be prudent for analysts not to assume this standard set in every case. Subsequently, detailed descriptions are provided of the standard set as it is clearly useful in numerous, although not necessarily all, contexts. These descriptions are illustrated with examples from work domain models of a home, a library, a military system, and a pasteurization plant.
