Harhalakis, GeorgeLin, Chang-PinA graphical representation schema - Updated Petri Nets (UPN) - has been developed to model rule based company policy specifications, in the context of computer integrated manufacturing systems. UPN facilitates the modeling of relationships between operations of various related application systems and the database updates and retrievals among various CIM databases. Based on this representation, a hierarchical modeling technique which includes refining and aggregating rules has also been developed. Application of the UPN is demonstrated in designing rule based systems for controlling and integrating the information between manufacturing applications, including Computer Aided Design, Computer Aided Process Planning, Manufacturing Resources Planning, and Shop Floor Control.en-USgraph theoryknowledge representationcomputer integrated manufacturingdatabasesmanufacturingManufacturing SystemsTechnical Report