| A role is an
    abstract definition of a set of activities
    performed and artifacts owned. Roles are typically realized
    by an individual, or a set of individuals, working together as a team. A project team member
    typically fulfills many different roles. Roles are not individuals;
    instead, they describe how individuals behave in the business and
    what responsibilities these individuals have. While most roles are realized
    by people within the organization, people outside of the development
    organization play an important role: for example, that of the stakeholder
    of the project or product being developed. | 
 A role, and its
    activities and artifacts Roles have a set of
    cohesive activities that they perform. These activities are closely related
    and functionally coupled, and are best performed by the same individual. Activities are closely
    related to artifacts. Artifacts provide the input and
    output for the activities, and the mechanism by which information is
    communicated between activities. | Role Sets |