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The following examples of typical KBE applicationsdemonstrate some of the considerable benefits to be gainedfrom its use.1) Lotus engineering. This used the integrated carengineer (ICE) system in the design of the LotusElise. ICE consists of a vehicle layout system, andmodules to support the design of suspension, engines,power-train, wheel envelope and wipers [17].2) The Boeing Commercial Airplane Group. This usesKBE as a tool to capture airplane knowledge to reducethe resources required for producing a design [18].3) Jaguar cars. The company’s KBE group devised asystem that reduced the time taken to design an innerbonnet from 8 weeks to 20 min [19].2.2 Problem to solve in a CAPP system based on KBEA stamping CAPP system should deal with all knowledgeincluding geometry, non-geometry, engineers experience,rules and criteria, results of tests and numerical simulation,or even successful cases, because of the complexity ofautomobile body panels. The knowledge is involved inperse fields, such as metal forming technology, metalforming mechanics, modern design methodology, numer-ical simulation technology, and artificial intelligence.Accordingly, the CAPP system has to solve the problemswith expression and application of all knowledge, andintegration of all multidisciplinary design.A CAPP system is essentially a set of instructions andguidelines on how to perform a complex procedure. Itdetails the inpidual sub-tasks, how they should be carriedout, in what order, and how the work should be doc-umented. Furthermore, as system requirements change, new solutions tend to evolve from existing ones, so com-puter applications and their descendants can outlive thepersonnel involved in their initial development. All in all, astamping CAPP system for automobile panels based onKBE should readily solve the following problems:(1) Representations for all knowledge.(2) Reasoning based on all this knowledge.(3) Appropriate operation features acquired from stampingfeatures and process rules incorporated with form-ability analysis.(4) Process routes based on process sequencing andprocess combination knowledge.(5) The control or management of process procedures forrapid response to all changes.3 Framework of a CAPP system3.1 The integrated master model for a CAPP systemTo solve all corresponding problems mentioned above, theintegrated master model is advanced at the system level tocontrol and frame the CAPP system for automobile panels. Itis a common concept and framework to generalize and spe-cialize the function, course control, process planning cir-cumstance, and activities involved in the development of anintegrated and intelligent system into abstract groups, and tomake themcarry out all contents and processes. This model issuitable for knowledge expression and application, processcontrolling, information integration, change response, etc.The intelligent master model (IMM) of stamping processplanning for automobile panels is composed of a knowl-edge base, process control structure (PCS), processplanning optimization (PPO), process information model(PIM), and linkable environment (LE), which are inte-grated and combined based on KBE. The structure of theIMM is shown in Fig.
1. The IMM of process planning isnot only the foundation of intelligent CAPP for automobilepanels, but also the integration of knowledge and methods,which combines the KBE system with the process plan-ning. With this model, KBE acts as a knowledge source todrive PCS, PIM, and LE, which makes process planningintegrated and associative.The PIM is a dynamic expanded information model, inwhich the information can be added and updated alongwith process planning. Using knowledge multi-expressionformat, the integrated information model of process plan-ning is built based on a feature model. For the hierarchyand framework of the features, semantic net and object-oriented methods are adopted to express knowledge andestablish an information model in which process knowl-edge, e.g. database, parameter, rules, and experience, act asrules and attributes of the objects, and where whole productknowledge acts as a framework for relationships of objects.With a process information model, the process planningcan be completed through knowledge-reasoning and de-cision-making based on knowledge encapsulated in theobjects.The PCS is a key point to ensure process planning isintegrated and consistent; it manages the process informa-tion model, process planning to generate stamping processplans and detail design, and controls the changes of theplanning. In IMM, the PCS comes into being dynamicallyalong with the process planning. If one part of PCS iscreated, it will monitor and control relevant planning andinformation subsequently. When results of process plan-ning are deleted, the corresponding PCS part will fadeaway accordingly.The LE provides several methods to deal with the linksamong process planning procedures, the geometry betweenproduct and detail design of workpieces. To achieveintelligent process planning for large complicated stamp-ings, there are problems to solve, i.e. linking of processplanning procedures, the geometry link between productand detail design of workpieces.