Objectives in Developing CAPP
In a foundry environment, CAPP systems essentially focus upon automating the planning and estimation activities. In particular, the objectives of a CAPP system for casting will be as under
- Estimation of weight of casting, core making and molding material from part prints/CAD models.
- Selection of cast metal/alloy and appropriate casting process.
- Estimation of manufacturing time in molding, core making and dressing.
- Estimation of cost per unit weight of a casting alloy or a mixture of core- making or molding material.
- Storage/Archival of major information on a particular casting for tendering or quotation purpose.
- Creation of database on estimates and updating based on actual shop data.
- Documentation of process planning sheets/information.
Compared to the CAPP systems for machining, CAPP systems for casting are not so well developed. Many of them are primitive in capabilities and are specific to the shop (foundry) and associated processes. The objectives listed above have not been comprehensively implemented in any CAPP system. [Ajmal and Dale, 1987]
The reported CAPP systems primarily follow one of the following CAPP strategies.
- Variant Process Planning
- Knowledge based (Expert) Process Planning