Class, Responsibilities, Collaborators (CRC) Cards
CRC Cards (Class, Responsibilities, Collaborators) are typically used when object-oriented design and development is preferred, and are helpful when there is a need to rapidly design one or more product features that may be instantiated as an object within the source code. First, two or more team members write down the names of the most critical classes involved in the feature on index cards. Second, the cards are fleshed out with lists of the responsibilities of each class and the names of collaborators (i.e., other dependent classes). Third, team members perform a role-playing exercise and assume the role of one or more classes while playing out a plausible scenario of the design.