Figure 1. The MKS Ontology of Manufacturing Operations, elaborated with Knowledge Specific to Semiconductor Manufacturing.

Ontologies such as this one, in effect, lay the ground rules for modeling a domain by defining the basic terms and relations that make up the vocabulary of this topic area. These ground rules serve to guide system builders in flashing out knowledge bases, building services that operate on knowledge bases, and combining knowledge bases and services to create larger systems. For one system to make use of either the knowledge or reasoners of another system, the two must have consistent ontologies.