INTEGRATION OF ENGINEERING PROCESS MODELING BETWEEN ENGINEERING DESIGN BOM AND MANUFACUTURING BOM BASED ON PRODUCT LIFECYCLE MANAGEMNT Kinya Tamaki, School of Business Administration, Aoyama Gakuin University, 4-4-25 Shibuya, Shibuya-ku, Tokyo, 150-8366 Japan Ayano Suhara, School of Business Administration, Aoyama Gakuin University, 4-4-25 Shibuya, Shibuya-ku, Tokyo, 150-8366 Japan Yutaka Kenmochi, SANDEN Corporation, 7 Nakanosawa, Kasukawa-mura, Seta-gun, Gunma, 371-0201 Japan Junpei Suzuki, SANDEN Corporation, 20 Kotobuki-cho, Isesaki-shi, Gunma, 372-8502 Japan Abstract It is impossible in practice to build and maintenance a single BOM for a product unit, because a lot of designing man powers are required for a huge task for multiple types and sizes of complex products. Therefore, unified generic product hierarchy model could be adopted for constructing comprehensive engineering design BOM (E-BOM) which covers with the whole NPI (New Product Introduction) products and continuously manufacturing products. This paper is to propose a methodlogy to focuse on the following topics: (1) to describe a unified generic product hierarchy model for comprehensive E-BOM which consists components and parts, corresponding to various types and sizes of all product variants, and (2) to propose a procedure of transforming the comprehensive E-BOM to the comprehensive manufacturing BOM (M-BOM) useful for production line balancing of the mixed-model assembly lines. The proposed methody had been applied to a case study which was to model engineering processes for new product developing projects of vending machines at SANDEN Corporation in Japan. Our collaborative researches had constructed a framework of innovative procedures for new product development and production preparation by means of a PLM system application and 3-dimensional computer graphic (3D-CG) simulator such as digital mock-up Keywords: Product lifecycle management (PLM), engineering design BOM (E-BOM), manufacturing BOM (M-BOM), 3- dimensional computer graphic (3D-CG) simulator 1 INTRODUCTION Located within the Research Center for e-learning Professional Competency (elpco), in the Aoyama Gakuin University Research Institute, the Tamaki Lab has been conducting studies into process engineering modeling and simulations associated with product lifecycle management (PLM) [1]. A PLM system is ideally an information process system that integrates the functions of the most companies [2]. The integration is completed through connecting and controlling the business processes for companies and manufactured products by means of various product data involved in BOM (bill of materials) database. A BOM refers to a product structure to which a hierarchy has been given in addition to a part list for design and production. The following case study is based on a joint research project between the elpco and Sanden Corporation (a leading manufacturer of refrigeration and heat exchange products, including vending machines) [3]. As a vending machine manufacturer, Sanden needs to meet the demands of beverage companies, who like to renew machine design and specifications each year. Since each new machine and component is designed individually to the brand specifications given by its customers, there are few parts that can be shared among models that are everdiversifying. This leads to redundancies in design and manufacturing processes, causing delays in development and adding to costs. The collaborative research with Sanden, the theme of which is "engineering process reform for frontloading the product development process". Sanden wants to "frontload" the development process (i.e., incorporate steps to resolve product development issues early in the design stage) to improve product quality while responding faster and more flexibly to customer needs. This paper is to propose a methodlogy to focuse on the following three topics. First issue is to describe a unified generic product hierarchy model for comprehensive E- BOM which consists components and parts, corresponding to various types and sizes of all product variants. Second is to propose a procedure of transforming the comprehensive E-BOM to the comprehensive manufacturing BOM (M-BOM) useful for production line balancing of the mixed-model assembly lines. Thus the hierarchy structure of the comprehensive E-BOM based on physical parts assembling sequences, should be changed to proper production hierarchy sturucture according to the comprehensive M-BOM based on task sequences in view of human operators working in the
mixed-model assembly lines. Thirdly, the proposed method has been applied to a case study which is to model engineering processes, according to multiple types and sizes for new product developing projects in the case of the vending machines at SANDEN [4]. Our researches have constructed a framework of innovative procedures for new product development and production preparation by means of a PLM system application and several 3D-CG simulators. 2 CASE STUDY OF VENDING MACHINS DESIGN AND PRODUCTION AT SANDEN CORPORATION Sanden s vending machines have been developed and designed by focusing on global environment conservation. Overall, it now enjoys 30 percent global market shares. Sanden in Japan has been manufacturing and distributing multiple types and sizes of vending machines based on the annual new product developing projects with nine main beverage manufacturers. As a case study we treat several types of front doors for the vending machines, the engineering process is modeled by a PLM system application and its validity is verified by using 3D-CG Especially, this case study focuses on limited types of the front doors which are selected types for two main beverage manufacturers and two sizes of vending machines as shown in Figure 1. The product architecture of the doors in the vending machines is divided into several functional modules. Figure 1: Front door types of two main beverage manufacturers and two Sizes of vending machines as a case study 3 CREATION METDOD OF INTEGRATED DESIGN BOM (E-BOM) 3.1 Integrated Design BOM Based on Categorization of Modular Product Architecture Our researche team developed a methodology that calls for a thorough analysis of the structure and components of each and every existing model, based on a new machine architecture. As shown in Figure 2, the front door in vending machines should be combined common functional modules and other components, and will be led to the creation of E-BOM to cover all models. To begin with, vending machines of different types and sizes were selected from several product brands. The structure of the door assembly was analyzed and the components were classified into functional modules (delivery bin, coin acceptor, merchandise display, etc.). The parts required for each functional module were further divided into the following categories: (1) parts common to all; (2) parts common to specific customers; (3) parts common to vending machines of a specific size. Coin acceptors, for example, are classified under (1), because standardized units are available on the market. 3.2 Unified Structured Comprehensive E-BOM Modeled by PLM System Application The engineering process modeling based on PLM system application could build various kinds of BOM database. We adopt a DELMIA Process Engineer (DPE) as the PLM system application. The feature of DPE provides PPR Hub for linking up and storing required process, product and resource which can construct comprehensive engineering database [5]. This PPR Hub as the comprehensive engineering database plays an important role to integrate individual BOM database required for each phase during the whole product lifecycle. The PPR HUB maps the entire planning content of DPE and all logical relationships between the process, product and resource data. The PPR Hub integrates the data used by the process planners, manufacturing engineers, facility planners, industrial engineers and production planners. Any item of information that is of significance within the context of integrated product and engineering process can be found in the PPR Hub data model. In Figure 3, the comprehensive E-BOM for vending machine doors was described as unified generic product hierarchy model based on the PPR Hub integrating the data such as required processs, products and resources. For each functional module, common part categories (1) to (3) were created, and the constituent parts of each module were defined (through shape data, etc.). By defining all modules down to the smallest part, a
Figure 2 Modular product architecture of front doors in vending machines Figure 3 Example of Comprehensive E-BOM for Vending Machine Doors unified E-BOM for door assemblies was created to cover the entire product line. It is impossible in practice to build and maintenance a single BOM for a product unit, because a lot of designing man powers is required for a huge task for multiple types and sizes of complex products. The operational tasks of the building and utilizing and maintaining individual BOMs will continuously increase, especially when the demands of NPI (New Product Introduction) increase. Therefore, unified generic product hierarchy model could be adopted for constructing comprehensive E-BOM which covers with the whole NPI products and continuously manufacturing products. Figure 3 illustrates an example of the comprehensive E-BOM for the vending machine doors. This unified generic product hierarchy model should be applied to the total product structure of the E-BOM by means of suitable hierarchy levels; front door, modular types, common components over the whole product, common sub-units within a beverage manufacturer,
common sub-units between small and medium and large sizes, and individual parts. Unlike previously single E-BOM, which had to be created for each product brand, the newly comprehensive E-BOM has a streamlined structure based on functional modules and common parts. As this comprehensive E-BOM requires additional data on the attribute information and shapes of the constituent elements, a E-BOM database was simultatiously created to serve as the PPR Hub. Feature information of essential parts or physical shape data are recorded and managed relating to the hierarchy structure of the cimprehensive E- BOM. The version history of a product, the order of the assemblies and parts required for it, etc. could be printed as reports. 4 CREATION METDOD OF INTEGRATED MANUFACTRUING BOM (M-BOM) In the previous chapter 3, the comprehensive E-BOM, corresponding to a huge task for multiple types and sizes of complex products, were already defined according to unified generic product hierarchy model. This model was described based on assembling sequences for whole functional modular units, components, sub-units, parts which compose in all varieties of Sanden s vending machines. As shown in Figure 4, the comprehensive E- BOM should be transformed to the comprehensive M-BOM which had unifined generic production hierarchy model by task sequences in view of human operators. Sanden has been assembling all variants of the vending machines with a mixed-model assembly line and sub-lines. The main role of the comprehensive M-BOM should be useful for production line balancing of the mixed-model assembly lines. Therefore, unified generic production hierarchy model of the comprehensive M-BOM should be defined according to the task sequences of human operators, working in the main line and sub-lines. Thus the hierarchy structure of the comprehensive E-BOM based on physical parts assembling sequences, should be changed to proper production hierarchy sturucture according to the comprehensive M-BOM based on task sequences in view of human operators working in the mixed-model assembly lines. In Figure 4, a procedure of transforming the comprehensive E-BOMs to the comprehensive M-BOMs is proposed as follows: 1) Make assembling drawings; assembling orders of modular units, to components, sub-units, and parts which compose a whole product, 2) Verify design for proper manufacturability and collision check among mutually assembled parts by digital mockup simulation, 3) Describe assembling precedence relationship among assembling modular units, components, sub-units, and parts, 4) Change from the assembling precedence relationship described with physical parts-oriented assembling, to work break structure (WBS) according to the task sequences of human operators. 5) By utilizing the PLM system (DPE), build the comprehensive M-BOMs according to generic production hierarchy model, and link up the attribute information from the comprehensive E-BOM to the comprehensive M-BOM database. To implement the proposed procedure of transforming the E-BOM to M-BOM could construct a significant bridge between engineering and production. In this procedure, special attention had to be paid to the modules that took a long time. Identifying the critical paths (i.e., the most time-consuming processes) is the key to streamlining process design. Collaboration between staff in different departments is also vital in integrating the knowhow of the designers and manufacturing engineers into a cohesive manufacturing BOM. Figure 4: A Proposed Procedure of Transforming the E-BOMs to M-BOMs
5 CONCULUSIONS This paper shows that the comprehensive E-BOM based on unified generic product hierarchy model would be more effective rather than an individual product unit model, especially in the case of a huge task for multiple types and sizes of complex products. In the case of the vending machines, the proposed hierarchy model was built and a E- BOM database was simultatiously created to serve as the PPR Hub by using a PLM system application (DPE). The mutual integration of multiple BOMs adding attribute information is a key issue of the product lifecycle management (PLM). The proposed procedure of transforming the comprehensive E-BOM to the comprehensive M-BOM, useful for production line balancing of the mixed-model assembly lines, could contribute to build significant interface between engineering and production. Additionally, the validity of the modeled engineering processes was verified in view of feasibility, productivity, and assembling sequence, by using a 3-dimensional computer graphic (3D-CG) simulator such as digital mockup 6 ACKNOWLEDGMENTS This research is supported by funding from Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (Grant No. 40188420); Process Modeling and Management of Innovative Business Strategies from the point of Product Lifecycle Management (PLM). 7 REFERENCES [1] Kinya Tamki (2006) Framework of Innovation Business Strategy Focusing on Sustaining Competitive New Product, AOYAMA JOURNAL OF BUSINESS, Vol. 40,No.4. (Japanese) [2] Saaksvuori, Antti and Immonen, Anselmi (2005) Product Lifecycle Management -2 nd. Edition-, Publisher:Springer. [3] Kinya Tamaki, Ayano Suhara, Yutaka Kenmochi, and Junpei Suzuki, Product Lifecycle Management with Engineering Process Modeling and 3D-CG Simulation, Proceedings of Abstracts and Papers (CD ROM), The 9th Asia Pacific Division Meeting of the International Foundation for Production Research, 2006, 257 [4] Ayano Suhara and Kinya Tamaki: Product Lifecycle Management with Engineering Process and Various BOMs A Case Study of Vending Machines Product Design and Product Design-, The 2007 Annual Meeting Record I.E.E.Japan, 2007, 1-S13(16)-(19). (Japanese) [5] DELMIA Process Engineer A Process Driven Approach to Process and Resource Planning http://www.delmia.com