The goal of the Organization Dependencies Description activity is to define relationships between capacities required by roles and organizations on the one hand, and services that realize them on the other hand. It also dedicated to the identification of resources and capacities to handle them.
Although capacities and services play a central role in this activity, the process
to be performed does not start from them. Organization Dependencies Description
activity starts from the identification and description of resources that are manipulated
by roles.
Resources in ASPECS are regarded as abstractions of environmental entities
accessed by boundary roles; in order to access resources, roles need specific capacities
that are now purposefully introduced (and then realized by services if necessary).
In this way dependencies of organizations on the real world are made
explicit.
Finally, this activity should also outcome with the description of interfaces used by the system to manipulate resources. When capacities and services are fully described, a test is necessary to ensure that each capacity is associated with its set of possible service-level realizations. This matching between service and capacity allows the initialization of a repository that may be used to inform agents on how to dynamically obtain a given capacity. Moreover it also proves that the hierarchical system decomposition is correct since the matching should validate the contribution that organizations acting at a given level give to upper-level organizations.
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Goal
The first aim of this activity is to identify resources manipulated by roles; this often implies identifying new capacities devoted to manipulate these resources. Moreover, since organizations depend on each other through service exchange, services provided by roles (while exploiting their capacities and accessing resources) can be identified in this activity.
This activity describes the interfaces used by the system to manipulate used
resource. When capacities and services are fully described, a check is necessary
to ensure that each capacity is associated with its set of possible service-level realizations.
This matching between service and capacity allows the initialization of
a repository that may be used to inform agents on how to dynamically obtain a
given capacity. Moreover it is also a verification of the goodness of the system
hierarchical decomposition. This matching should validate the contribution that
organizations acting at a given level give to upper-level organizations.
Input
Capacities identified during capacity identification or role behavior description activities are described and associated to corresponding implementations (services) in this activity. The solution ontology details concepts associated to roles, and may thus provide elements to refine the knowledge manipulated by roles. This knowledge is the basis of capacity and associated services descriptions.
Output
For each organization, capacities, services and resources are added to previously designed Capacity Identification class diagram. A text document is also produced during this activity to report the description of capacities, service interfaces and a table summarizing a possible matching between capacities and services.
MAS Meta-Model Elements
Define(Service), Relate(AgentRole, Service), Relate( Organization, Service), Define(Resource), Relate(AgentRole, Resource), Relate( Capacity, Resource), Relate(Capacity, Service).
Work to be done
It will be assumed that an organization is able to provide a service if the service is provided by of one of its roles. A role may provide a service if it owns a capacity with a compatible description and it manages/supervises a work-flow where:
- the service is implemented in one of its own behaviors; or
- the service is obtained from a subset of other roles of the same organization by interacting with them using a known protocol; this is a service composition scenario where the work plan is a priori known and performance may be someway ensured; or
- the service is obtained from the interaction of roles of the same organization but the work plan is not a priori known and the service results in an emergent way.
In the last cases, the management of a service provided by the global organization behavior, is generally associated to one of the organization’s roles. It can also be managed by at least one of the representative of the various holons playing roles defined in the corresponding organization.
Methodological Guidelines
Service exchange is often a need arising from the beginning of the requirements analysis phase. In the proposed approach, some services can be identified by exploiting relationships among use cases, especially those crossing different organizational packages. If two use cases belonging to two different organizations are related by an "include" or "extend" relationship, it is very likely that the corresponding organizations will cooperate in a service exchange.
Identification of resources can be done by identifying resources that can be
accessed and manipulated by different roles: databases, files, hardware devices,
etc. Resources are external to the role; a capacity is generally used to interface the
role with the new resource. Each capacity needs a realization in form of a service
that is purposefully defined for that.
