Annals of the CIRP Vol. 56/1/2007 -175- doi:10.1016/j.cirp.2007.05.042 Knowledge Management in Process Planning B. Denkena 1 (1), M. Shpitalni 2 (1), P. Kowalski 1 , G. Molcho 2 , Y. Zipori 2 1 Institut für Fertigungstechnik und Werkzeugmaschinen (IFW) Produktionstechnisches Zentrum Universität Hannover 2 Laboratory for CAD and LCE, Faculty of Mechanical Engineering Technion - Israel Institute of Technology 32000 Haifa, Israel Abstract Considerable research and development efforts have been devoted to Computer Aided Process Planning (CAPP). Nevertheless, because the CAPP problem is complex and is characterized by many interdependent technical and business parameters and variables, no viable off-the-shelf solution is yet available that can be easily or widely implemented in industry. This paper presents an overview of the CAPP field and describes a holistic component manufacturing process planning model based on an integrated approach combining technological and business considerations. The model was derived based on available literature, an overview of the state-of-the-art in Digital Manufacturing, Product Lifecycle Management (PLM) and CAPP solution providers, and a survey of Small Medium Enterprise (SME) manufacturers. This model will form the basis for developing improved decision support and knowledge management capabilities to enhance available CAPP solutions. Keywords: CAPP, Abrasive processes, Knowledge management. 1 INTRODUCTION One of the most important steps in converting a design concept into a manufactured product is process planning. Such planning determines the manufacturing operations, operation sequence and resources required to manufacture a product based on an engineering drawing or a CAD model. A process plan elaborates the machines, setups, tool specifications, operation time estimates, etc. required to convert raw material into a part [1]. Traditionally, process planning was performed manually from scratch, hence requiring retrieval and manipulation of a great deal of information from many sources, including established standards, machinability data, machine capabilities, tooling inventories, stock availability and existing practice. Much research and development has been devoted to developing a computerized solution for process planning - Computer Aided Process Planning (CAPP). Nevertheless, because the CAPP problem is complex and characterized by many interdependent technical and business parameters and variables, no viable off-the-shelf solution can yet be easily or widely implemented in industry. Moreover, because expert process planners are becoming an expensive and rare resource in industry, their productivity, effectiveness and consistency must be enhanced through improved decision support tools and knowledge management capabilities. In this paper we have developed an ontology for the “extended" process planner environment and the process planner decision-making process model. These models are used as the basis for developing decision support and knowledge management templates and capabilities to support the process planning decision process for component manufacturing in the cutting and abrasive process domain. In these models a holistic approach was adopted that incorporates traditional technological aspects of process planning as well as complementary business aspects. Since the process plan is used in production scheduling as well as in machine control, it affects production efficiency, final cost and product quality [2]. Hence, process planning has a major impact on manufacturing profitability. Emphasizing the business aspects of CAPP will enhance existing CAPP solutions that currently focus on technological feasibility and optimization. In addition, this paper presents PLM/CAD-CAPP solutions available in industry today from leading providers such as UGS, PTC, and Dassault Systemes, as well as their current development directions. Moreover, we discuss some additional complementary capabilities, identified during the literature review, market survey and industry survey, required to complete the holistic solution. 1.1 CAPP Overview There are two basic approaches to computer-aided process planning — variant and generative [3]. Variant CAPP was the first approach used to computerize planning techniques. It is based on the notion that similar parts will have similar process plans. Part coding and classification based on group technology are used to implement this concept. A “standard” plan is formulated and stored for each part family [4]. Variant CAPP has the following advantages: (a) once a standard plan has been written, a variety of components can be planned; (b) programming and installation are comparatively simple; (c) the system is understandable, and the planner has control over the final plan; and (d) it is easy to learn and use. Yet several problems are also associated with variant CAPP: (a) the components to be planned are limited to previously planned similar components, and process optimization is not included; (b) experienced process planners are still required to modify the standard plan for a specific component; (c) variant planning cannot be used in an entirely automated manufacturing system without additional process planning [2]. Generative CAPP envisions creation of a process plan from information available in a manufacturing database