The essence of this scenario is that complex equipment and machines behave as coordinated objects according to the consistent models provided. The models represent a consistent set of interactions and relationships between factory information and physical entities. The consistency of the model structures is ensured through standardization, and the consistency of the model relationships and contents is ensured by rule-based systems under factory and enterprise control. Model behaviors incorporate equipment control within inherent equipment capabilities (e.g., alarm levels, localized control/feedback, and state/process sequencing), as well as external behaviors such as publication of information required for local or enterprise systems (e.g., process control tolerances for design engineers at remote sites and interaction with other objects or services).

The underlying communication services are tailored to distributed object and model communication. Objects are aware only of other appropriate objects and not of the underlying communication mechanisms. The actual routing of messages and information is a function of the underlying distributed communication services and is not a concern of objects. Standardized object communication classes are inherited by objects used in the factory and enterprise, and so they may share certain common communication capabilities as well as have specific capabilities as required. Selection of appropriate routing, broadcasting, distribution, multicasting, flow, management, and other protocols and algorithms is contained within the factory or enterprise communication classes.

The above scenario, while emphasizing the object nature of equipment, does not underestimate the importance of the underlying communication mechanisms, object modeling, knowledge management, tools, and resources. In addition, it does not underestimate the substantial amount of industrial, academic, and governmental cooperation necessary to achieve the research, development, and general availability of the hardware, software, and standards needed to bring this about. (Note: This author has been involved in all of these facets and has great respect for the magnitude of the work necessary to bring them into reality.)



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