Task: Define Service Model
Task sourced from Gaia
Purpose
The purpose of this task is to identify the main services, intended as coherent blocks of activity in which agents will engage, that are required to realize the agent’s roles, and their properties.
Relationships
RolesPrimary Performer: Additional Performers:
InputsMandatory:
    		Optional:
      Outputs
        Process Usage
        Main Description
        This task consists of specifying services properties such as inputs, outputs, preconditions and post - conditions. The services that compose an agent are derived from the list of protocols, and from the organizational activities of the roles it implements. At one extreme, there will be at least one service for each parallel activity of execution that the agent has to execute. However, even for sequential activities of execution, there may be a need to introduce more services to represent different phases of the agent execution.See Developing multiagent systems: The Gaia methodology (p. 362-363)  for more information about this task.
        Steps
        Specifying service inputs and outputs
        Inputs and outputs to services should be derived from both the protocols model (for services involving the elaboration of data and knowledge exchange between agents) and the environmental model (for services involving the evaluation and modification of environmental resources).
        Specifying service preconditions and post-conditions
        Pre- and post conditions represent constraints on the execution and completion, respectively, of services. These are derived from the safety properties of a role, as well as from the organizational rules, and may involve constraints on the availability and the specific values assumed by either environmental resources or data and knowledge from other agents.
        Alternatives

        The purpose of this Medee Task Variability is to extend the Gaia Task Define Service Model in order to insert Medee Basic roles, and to replace original work products by the related Medee Work Products variability.

        More Information
        Supporting Materials
        Whitepapers