System Design by Composing Structures of Interacting Objects

This paper describes the outline of an object-oriented design technique denoted role modeling, emphasizing the ability to compose parts of a design. The purpose of role modeling is to achieve separation of concerns, allowing the designer to consider different aspects, or the same aspect at different levels of detail, more or less independent of other aspects of the overall design. A role model represents the concept of a structure of communicatingobjects; each object being represented by a role to be 'played' in the context of this role model. Each role model is considered a design of a separate aspect of some overall design. Composition of designs is achieved by synthesizing roles in several role models, constructing more aggregated and specialized roles and role models.