On the Integration of Roles in the UML

Conventionally, the state space and behavior of an object is determined when the object is created. Attributes and methods are not allowed to be attached to or retracted from an object during its lifetime. In other words, it is not feasible for an object to change its type dynamically. Furthermore, it is not possible to define several different views on an object allowing to exhibit a specific view to another object and hiding part of its features to a particular object. As a consequence, the concept of an object does not reflect appropriately real-world entities which may change their behavior and exhibit only part of their behavior towards another real-world entity. The concept of a role has been considered as an appropriate step forward to solving these kinds of problems. In this paper, we examine the concept of roles and elaborate a proposal for the integration of a clear concept of roles in the UML.