Pattern-Oriented Software Architecture, Volume 1, A System of Patterns

Notations

Class-Responsibility-Collaborator Cards

Class-Responsibility-Collaborators (CRC-) cards [BeCu89] help to identify and specify objects or components of an application in an informal way—especially in the early phases of software development.

A CRC-card describes a component, an object or a class of objects. The card consists of three fields that describe the name of the component, its responsibilities, and the names of other collaborating components. The use of the term ‘class’ is historical [Ree92], and we use CRC cards for other kinds of components or single objects as well.

Object Modeling Technique

The Object Modeling Technique (OMT) [RBPEL91] is a widely-used object-oriented analysis and design method. OMT consists of three models, the object model, the dynamic model and the functional model. We adopt the notation only for the object model, to show the static structure of interacting components. The object model describes objects or classes, their attributes, methods, and relationships. We also use the boxes that represent classes in OMT for other kinds of components. OMT represents association, aggregation, and inheritance relationships between components by lines that connect the components. The basic concepts of OMT’s object model notation are illustrated below:

Component

A rectangular box, denoting the name of the component and optionally its attributes and ...