The goal of this activity is to describe the sequence of interactions occurring among roles involved in each scenario. Scenario description is done just after OID and IRI activities and at this stage it is possible to assign an organization and a set of interacting behaviors (enacted by involved roles) to each requirement. The challenge consists now in describing how these different roles interact to realize the scenario. Scenarios are drawn in form of UML sequence diagrams and participating roles are depicted as object-roles (the role name is specified together with the organization it belongs to).
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Goal
The goal of this activity is describing the sequence of interactions among the roles involved in each scenario. Scenarios description occurs just after OID and IRI activities and it is now possible to assign to each requirement an organization and a set of interacting behaviors (enacted by involved roles). The challenge now is to describe how these different roles interact to realize the scenario.
Input
Scenarios are deduced from the set of text descriptions of the system usage scenarios, and from the output of the OID and IRI activities.
Output
Scenarios are described using an adapted version of UML sequence diagram. Each object in the diagram represents an AbstractRole, and we name it with the following syntax:< role name >:< organization name > The message in the sequence diagram may either signify an event generated by the external environment or an interaction/communication between roles. The meaning of this message will be later refined in the Agent Society Design Phase.
MAS MM Elements
Quote(Interaction), Quote(AbstractRole), Quote( Relate( AbstractRole, Interaction)).
Work to be done
A scenario description explores all the possible paths of an Organization Identification diagram. A path describes a set of interacting roles working to achieve a required behavior of the system. It is composed by interactions between roles of the same organization identified during the IRI activity and interactions between roles of different organizations that have not been described yet. A role can appear in several scenarios.
This activity is thus at first a way to verify that usage scenarios are effectively
fulfilled. Then it also allows checking if the set of identified organizations
is sufficient or not and to clearly describe the relations among the identified organizations.
This last point will provide the initial elements to determine the future
holonic structure of the system.
Methodological Guidelines
No specific guideline have been identified yet for this activity. It resembles the classical scenario description activity of object-oriented design and the knowledge of the related techniques has been always sufficient in the conducted experiments.
