A Manufacturing Process Information Model for Design and Process Planning Integration

Shaw C. Feng and EugeneY. Song, Manufacturing Engineering Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland, USA

Abstract exchanged among, and shared by, different design, The National institute of Standards andTechnology (NIST) engineering, and manufacturing systems. Design and Process Planning Integration (DPPI) project is At the National Institute of Standards and Tech- developing an open, neutral manufacturing process object nology (NIST), the Design and Process Planning In- model to enable software interoperability among preliminary tegration (DPPI) project addresses the needs for product design, process planning, and manufacturing execu- tion. This has been used as the basis for devel- improving communications between design and pro- oping the IS0 16100 standard: Industrial automation systems cess planning activities, especially in the early de- & integration - Manufacturing software capability profiling, Part sign phase. Considerable emphasis is initially being 2: l’nformation models for interoperability. placed on the conceptual stages of both design and TQis*paper describes an object-oriented manufacturing process information model in the Unified . processplanning (Nederbragt et al. 1998).The main The model comprises classes on the necessary manufactur- goal of the DPPI project is on the information ex- ing information, such as artifact, manufacturing activities, change and interoperability between design and workpiece, manufacturing equipment, estimated cost and time, manufacturing processplanning software systemsfor and manufacturingprocess sequences. Major manufacturing activities include setup, workpiece handling, loading/unload- mechanical products. To support the seamlessinte- ing, and processing. This model is capable of describing the gration of preliminary design and preliminary pro- hierarchical structure of the information representing manu- cessplanning, the DPPI project established an open, facturing processes of an artifact by means of recursive defi- neutral manufacturing process object model using nition. Also, the model includes the representation of concurrent object-oriented technology. This model supportsthe activities, alternative activities, and parallel activities. Further- more, this model provides software developers with the infor- representationof manufacturing activities, resources, mation foundation for developing new process planning cost, and time. The IS0 16100 Part 2 (Industrial au- systems such that time can be signifi- tomation systems& integration - Manufacturing soft- cantly reduced. 1‘ ware capability profiling - Information model for Keywords: Manufacturing Process Modeling, Manufacturing interoperability) working draft has been developed Information, Object Model, Product Development, Systems based on this model. The IS0 16100 working draft Integration consists of five parts: Framework for interoperability, Information models for interoperability, Interface 1. Introduction protocols, Profiling method and templates, and Con- formance test methods, criteria, and reports. The Automotive Interoperability Study estimates that the U.S. automotive industry has to spend about $1O9 USD a year to overcome information barriers 2. Related Research Work in and poor interoperability among computer-aided de- Manufacturing Information Modeling sign (CAD), computer-aided process planning, and To achieve software interoperability, information computer-aided manufacturing systems. About $9 x models are necessaryand critical to specify common 10’ USD is used to repair and replace unusable data terms and programming interfaces. In design, a prod- files (Brunnermeier and Mar&in 1999). A key solu- uct model is being developed in IS0 10303 (infor- tion to the problems will be standard programming mally known asthe STandardfor Exchangeof Product interfacesthat will allow information of design, pro- data - STEP) (IS0 1994). STEP includes representa- cess planning, and manufacturing execution to be tions of geometry, topology, dimension, tolerance,

I feature. material, product configuration, and so on. design goals of ALPS include the support fc Manufacturing information modeling efforts have decomposition, parallel tasks, synchronizat been focused on manufacturing resource capability tasks, alternative tasks, sequences,resource r modeling, process plan modeling, and manufactur- tions, critical task sequences,and informatic ing cost modeling. Several manufacturing models nipulation operatives (Catron and Ray 1991 have been developed, but they are not in the stan- model is in an entity-relationship model. Ho dardization stage. the model is not object oriented. STEP AP2 1: application protocol (AP) within STEP that sp Manufacturing Resource Capability Modeling the exchange, archiving, and sharing of nur A manufacturing resource information model is control (NC) processplans for machined part! often used in resource selection and processcapabil- FDIS 1995). The model supports sequential ity evaluation. A manufacturing resource capability ties. It does not support parallel or concurrent model representsthe information on the function and ties. It also does not support manufacturing cc characteristicsof resources that contribute to the pro- time information exchange. cesscapability. Several manufacturing resourcecapa- bility models have been developed. A manufacturing Manufacturing Cost Modeling information model supports the product realization Production costs are primarily committed process. It only focuses on the information of design early design stage.It is important to model al for manufacturability on the factory level (Giachetti mate the costs to guide designersto make sot 1999). The two manufacturing capability models to cisions to lower product costs. There are three support concurrent engineering are capable of repre- cost-estimating methods used in industry: th senting the resource capability on the workstation metric-based approach (Milehan et al. level (Song, Chu, Cai 1999; Mollina, Ellis, Young Boothroyd and Reynolds 1989), feature-ba 1995).A product and manufacturing capability model preach (Ou-Yang and Lin 1997), and activit: for CAD/CAPP integration focuses on information approach (Park and Kim 1995, Ioannou and I aboutmachine tools, machining processes,operations, 1999). Activity-based cost (ABC) estimation j and cutting tools (Gao and Huang 1996).A model of on the costs of all manufacturing activities. A manufacturing resource information focuses on mill- guide process planners to lower manufacturi ing and turning machine tools, cutting tools appro- by controlling and reducing related manufi priate to the processes of milling, drilling, and so on activity through identifying non-value-addinf (Jurrens, Fowler, Algeo 1995). An object-oriented ties. The integration of cost models with man manufacturing resource modeling for process plan- ing resource capability models and process p ning includes shape capability, dimension and pre- models has to be further developed, for an in cision capability, surface finish capability, and model is necessaryto enablesoftware interope position and orientation capability (Zhang et al. 1999). These models provide a foundation for de- Summary of Manufacturing Information veloping the manufacturing process information The abovementionedmodels have not bee! model described in this paper. fully integrated with each other or with a information model. Some specific issue Process Plan Modeling addressedare as follows:

Process plan modeling is to describe the process l Most published process plan models 1 plan strategy of a manufacturing process. A process detailed process planning, not the pre: plan model includes a hierarchically structured pro- process planning in the early product ( cess plan: generic plan, macro plan, detailed plan, ment stage,and needto be extended to i and micro plan (Ming, Mak, Yan 1998). A Language the following manufacturing informal for Process Specification (ALPS) has been designed hierarchical structure of manufacturin as a to support the description of process ties, workpiece information, processi plans used in the discrete manufacturing industry.The and manufacturing cost.

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