The purpose of this section is to summarize the current trends of applications of MASs to P&S in manufacturing. As previously explained, P&S activities are two contiguous aspects that are often confronted in an integrated way by MAS applications. The objective is to examine the possibility of exploiting the different modeling alternatives, in terms of system architectures; agent roles and types; and interaction protocols, in order to define P&S systems for manufacturing. This section reviews some key concepts arising from successful approaches proposed in the literature over the last 10 years. A more complete and detailed summary is provided in Chapter 6.

The basic architecture schemes that have been introduced and adopted for MASs in manufacturing correspond to the three main agent organizations that follow [42], [43]:

• Hierarchical architecture: agents operate at the different levels of a hierarchy that basically reproduces the hierarchical distribution of responsibilities and control in a manufacturing organization. Therefore, higher level agents control the activities of lower level ones, and communication usually takes place through the vertical levels of the hierarchy. This kind of model does not exploit the potentiality of an MAS, but adapts agents to a pre-existing bureaucratic organization. Flexibility is thus clearly reduced and, rather than a decentralized and distributed solution typical of agent-based systems, it takes the form of a monolithic centralized system.

• Federation architecture: agents are organized in small communities or clusters, depending on their functions, and other agents play the role...