This part of the book thoroughly describes the use-case construct as well as other, related constructs needed in a use-case model.

The first few chapters describe use cases and actors, and give the background necessary to understand the descriptions of use-case patterns, blueprints, and common mistakes in Parts III through V of this book. Most of the patterns and blueprints also make use of relationships between use cases and actors. Therefore, this part also includes a collection of chapters describing the different kinds of relationships used in use-case modeling. These chapters can be read more superficially if the only goal is to achieve enough basic knowledge to be able to get a grasp of the patterns and blueprints, but should be studied in more detail by use-case modelers in spe.

The part also includes two chapters on how to describe use cases and use-case models. It is not necessary to read these chapters to understand the rest of the book, but they will prove useful to anyone writing or reviewing use-case descriptions.

Part II ends with an introduction to analysis classes used in platform-independent realizations of use cases. This chapter gives basic information on the subject, sufficient to understand the last section of each pattern and blueprint chapter.