We regard simulation as a set of interaction episodes between partaking agents in an agent-based simulation. In order to structure the interaction we use commitments, and the semantics of such commitments is an analogy to a two-phase commit scheme used in distributed databases. A commitment is a contract between the involved agents to reach and preserve a specified goal, during a specified time. Here we define the semantics, describe the messages and outline administrative issues. The full strength of the model is reached when an initiator needs to make commitments with a number of other agents. It then awaits the replies, and then, depending on the replies, it either confirms or rejects proposed commitments. Hereby it accomplishes an analogy to an atomic action when a two-phase commit scheme is used. When the commitment scheme is applied to a simulation, a crucial part of the design is to model the requirements for accepting commitments during simulation. We introduce the concepts of an acceptance function and acceptance domains that are used to express these requirements. An example from battle field simulation is given. With the proposed model simulated objects may quite easily be replaced by real objects. With the right kind of interface, real trucks and other entities may partake in real time operations, while other entities are simulated.

I agentbaserad simulering definierar vi ett scenario som en mängd interaktionstillfällen. Varje sådant interaktionstillfälle mellan agenter (och de enheter de representerar) uttrycker vi med hjälp av begreppet "Commitment". För distribuerade databaser är detta ett väl beprövat koncept, och här utvidgar vi det till att gälla generellt för agentinteraktion.