AN ILLUSTRATION OF OBJECT-ORIENTED DATA MODELING WITH SOME MRP-RELATED ENTITIES

Recent manufacturing engineering research has two important emphases: automation and integration. Automation utilizes computer technology to enhance die functionality of manufacturing functions whereas integration focuses on the architecture and ingredients needed for the manufacturing functions to work as an integrated system. A few integration architecture models have been proposed, such as NIST MSI and ESPRIT CIM-OSA. All the models stress the importance of manufacturing information integration.
To achieve manufacturing information integration, an integrated database is mandatory. The previous database technologies, namely hierarchical, network, and relational, have failed to provide the needed characteristics for total information integration. As an emerging database technology, the object-oriented database (OODB) shows great potential in manufacturing information integration. The object-oriented database has rich semantic modeling capability (both structural and behavioral) that is much needed in modeling manufacturing entities in an integrated environment.
In recognition of the potential of the OODB, research is underway to analyze and model the structural as well as the behavioral aspects of some of the manufacturing entities (data) pertaining to a subset of a generic production management and control system, namely material requirements planning (MRP) and capacity requirements planning (CRP). Typical data include item master data, product structure, inventory data, routing data, production facility data, tool data, etc. As a verification/validation process, a prototype MRP/CRP system will also be implemented.
In this paper, the initial results of the research will be presented. The item master and product structure data, as a prerequisite for MRP, are modeled and implemented in a commercial OODB. Comparison of the OODB approach and the traditional rile approach will be discussed.