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Figure 6.5 illustrates the resulting event categories defined by the
GRAMS reference model:
(1) Events generated on the macro-level and affecting just the macro-
level.
Examples are environmental events (like beginning to rain, strike
of a lightning, collapse of a building, etc.). As the embedding of
entities is defined on the macro-level, these type of events may
also be used to model some kind of agent creation at a specific
point in time and subsequent placement of new agents into the
environment.
Events of this category do not directly influence the state space of
entities, but only the environment
and, in case of agent creation,
the entity set
ENT
and embedding
emb
.
E
(2) Events generated on the macro-level and directly affecting entities.
Examples are events that represent perception (e. g., receiving a
radio communication) as well as events resulting from conflict-
ing actions of two agents as defined by model constraints (see
Section 6.6.4).
(3) Events generated by an entity (in general by an agent) and affecting
only the same entity.
This kind refers to the events used by the agents to control their
own behavior (see Section 6.6.2).
Distinguishing the different event categories provides several bene-
fits:
Provide interface specifications
Exogenous events associated with an agent (category (2) in Fig-
ure 6.5) serve as an interface specification and define precisely which
event types an agent can process.
Enable encapsulation and component-based development
Defining interfaces is a necessary prerequisite to enable encapsula-
tion (i.e., inner structure and behavior of an agent is irrelevant to
