In order to be able to monitor the system and the constraints that it has to adhere to, a specialised infrastructure
has to be defined. This infrastructure is captured in the observation model. It ususally consists of
monitors or observers that acquire data about the state of a specific agent, a group of agents, or
parts of the system and check whether the specified constraints hold. Additionally, it contains controllers
that react to the violation of these constraints in order to restore the constraint in question. This distinction is
detailed in Observer/Controller Architecture and can be found in other kinds of
operationalised feedback loops such as the MAPE cycle.
The observation model can be related to the agent architecture—in case the constraints can be observed on the
agent level—or to the system architecture—in case the constraints need more global data to be observed. This
corresponds to the different varieties of the Observer/Controller Architecture, in which the Observer and the Controller
respectively can be located at different levels of the system. In many cases, several observer/controllers on different
levels of the system are required to handle different constraints.
Apart from determining the level on which the monitoring infrastructure has to be located, the observation model also
has to describe the interaction between the agents and the monitors, as well as the interaction between the monitors
and the controllers that react to constraint violations.
|