CRC-cards for Product Modelling

This paper describes the CRC (class, responsibility, collaboration) modelling process for building product models. A product model is normally represented in an IT system which contains data, information and knowledge on industrial products and their life cycle properties e.g. manufacturing, transportation, service and decommissioning.

A main challenge when building product models is to collect and document the product related data, information and knowledge in a structured way. CRC cards are index cards (or computerized versions of these) which are used to record proposed classes, the behavior of the classes, their responsibilities, and their relationship to other classes (collaboration).

CRC modelling gives an effective, low-tech method for domain-experts, programmers and users to work closely together to identify, structure, understand and document a product model. CRC cards were originally introduced back in 1989 for software developers in general as a tool for defining an object oriented analysis model.

In this paper CRC cards and the associated object oriented modelling techniques are adapted to product modelling. CRC modelling includes for instance: Organizing the CRC modelling team, educating relevant personnel (domain experts, programmers and users), and iteratively performing the steps of CRC modelling (find classes, find responsibilities, define collaborators etc.).

CRC modelling covers some of the basic work before implementation of the product model in standard configuration software or programming the system. The CRC cards can be used to document the system through the entire life cycle (analysis, design, programming and maintenance). This article focuses on the application of CRC-cards in the analysis phase.

The concepts and methods for modelling product knowledge have been tested in Danish industrial companies. The article presents a case study from Alfa Laval Separation.