| The primary objective of this research was to develop a prototype manufacturing process planning and scheduling system with a manufacturing cost estimating module. This prototype system has five components. These components include a manufacturing database, form feature recognition, process alternative generation, scheduling state evaluation, and estimated cost calculation. This prototype system is implemented in the C language and embedded with the CLIPS expert system. The scheduling and manufacturing facility information are stored in one database which is created by the ACCESS database system. The user creates the blank model, removal volume model, and enters other related information, such as the material of the design part, requested due date, and number of parts requested. The form feature recognition performs the feature extraction function to construct the manufacturing units. The process alternative generation produces operation assignments for the process plans. The scheduling state evaluation performs the manufacturing sequence establishment and validation. Finally, the estimated manufacturing cost is generated by using the activity-based costing principles which are based on the cost drivers of manufacturing and nonmanufacturing activities. Several features which improve the cost estimation and process planing are also included in this prototype. These features are as follows: (1) retrieval of the manufacturing feature information from a 3-D CAD design by using a mixed graph-based and rule-based algorithm, (2) enhancement of the manufacturing flexibility by exploring multiple alternative processing, (3) improvement of the information integration by including the manufacturing facility database, (4) selection of the process sequence by verifying the facility scheduling status, and (5) calculation of the estimated cost by using the activity-based costing principle. |
