RULE BASED SPECIFICATION FOR ...

RULE BASED SPECIFICATION FOR COLLABORATIVE DESIGN

Guillaume Ducellier*, Benoit Eynard*, Emmanuel Caillaud**, * Troyes University of Technology 12 rue Marie Curie, BP2060, 10010 Troyes Cedex, FRANCE ** INSA Strasbourg Institut Nationale des Sciences Appliquées (INSA) 24, boulevard de la Victoire, 67084 Strasbourg Cedex, FRANCE

ABSTRACT Collaborative Product Development Systems (CPD) tends to enhance product performance, time-to-market and traceability. The researches illustrate the benefits of CPD methods and tools for engineering issues. However, organizational and technical difficulties occur while using a CPD and limit these benefits. Adding to that, Knowledge reuse issues have to be taken into account to limit design flaws. The research presented in this paper is based on the cross-domains of CPD and Knowledge Reuse researches. It proposes to improve exchanges occurring during the use of expert applications (Computer-aided Design, Finite Element Analysis, etc.) in a PLM. In this context, set of rules are defined to enable knowledge reuse and new specification for specific data transfer protocols are proposed. Finally, an existing PLM application is customized to propose the new product data management possibilities developed. To conclude, first results are presented and methods for evaluating are presented.

Keywords Collaborative Product Development ; Knoweldge Reuse ; STEP ; Finite Element Analysis

INTRODUCTION First, Collaborative Product Development (CPD) is a key objective in the research of product performance, better time-to-market and traceability. Researches developed in this area illustrate the common admitted advantages of CPD methods and tools for engineering issues. However, organisational and technical difficulties result from the use of Collaborative Product Development methods and techniques and tend to decrease the advantages of CPD. Second, Knowledge reuse becomes a key factor for reducing time, cost and flaws during Product Development activities. Knowledge reuse in the domain of CDP presents human and technical difficulties that are not currently support by existing methods and tools. Our research is based on the cross-domains of Collaborative Product Development and Knowledge Reuse researches. In this paper, we propose first to base our research on prior development conducted in the domains of Product Lifecycle Management. Existing standard of exchange protocols such as STEP are described and Collaborative Product Development researches are identified. Second, Use Cases are set using existing applications such as CAD and PLM Systems. These Use Cases are used to illustrate the lacks in existing data standard of exchange protocols and the problems occurring during the use of CAD and PLM Systems for CPD. Third, we propose to enhance existing CAD and PLM Systems by implementing Knowledge reuse possibilities to the data standard of exchange STEP. Based on this enhancement of STEP possibilities, an existing PLM application is customize to propose new product data management possibilities for enabling knowledge reuse during Collaborative Product Development phases. To conclude, the paper describe methods for evaluating our results based first on the use cases developed above and second on Collaborative Product Development Projects developed in Troyes University of Technology. COLLABORATIVE PRODUCT DEVELOPMENT

CPD aims to enhance product performance, better time-to-market and traceability. The researches conducted in the domain of CPD present multiple approaches. The first presents approach that regroups CPD functionalities into a single application. Some of the researches conducted in this domain are presented in the section 1. The second approach tends to organize the managing of the data into the lifecycle of the product, through the use of a Product Lifecycle Management Application. An overview of the researches conducted in this domain is presented in section 2. SECTION 1: COLLABORATIVE PRODUCT DEVELOPMENT APPLICATIONS In this section, a short overview of current researches in the field of collaborative product development is presented. In this domain, multiple researches are conducted using web-based architecture. [1] propose a synthesis based on surveys to define key requirements for CPD. In their research, the authors concentrate on the need for specification data and parameter information sharing. This research presents an approach of a system architecture enabling a CPD application fully web-based. It is based on industrial specifications and highlights the need for CPD applications. However, because it mainly concentrates on the specifications and on the technology used, it hardly proposes methodologies for CPD. [2] present a collaborative CPD Application offering common communication tools. These researches are based on product specification methodologies such as GANTT and SADT in order to develop, share and save data regarding the project management functionalities. Fully web-based oriented, these researches are offering an integrated approach for CPD. However, in this research the methodologies enabling the use of the application are hardly described and the difficulties resulting from the use of CPD do not clearly appear. [3] deal with the use of Web technologies in mechanical design and structural analysis fields. It details the software architecture of Teamproject. One of the added values offered by this Web CSCW is the translation of CAD and FEA data into VRML format. It extends the product data review to all the team members involved in a project. Indeed, the reading of the VRML data can be ensured by the most used web navigator (like Internet Explorer and Netscape) with the aid of a free plug-in. To summarize, the proposed Web CSCW provides a simple and efficient access to mechanical design and structural analysis data in a real collaborative engineering approach. Other researches presented common communication tools and data management functionalities can be also mentioned [4] [5]. SECTION 2: PLM APPLICATIONS In this section, a short overview of current researches regarding PLM is presented. In order to understand the way Product Data Management Systems are currently organized, it is first necessary to list some of their most important functionalities [6]. A PDM System is able to: - capitalize and structure technical data - classify data - deal with product evolution (modification of data, creation, suppression of information) - ensure the access of the product data in a secure way - control the processes - manage project organization, teams and roles - distribute the product data - enable the user to visualize the product data Based on these requirements, some developments have been conducted in the research community and industries. These researches led to the development of commercial PDM and few companies became leaders of the domain (Dassault Systèmes, MatrixOne, PTC, Unigraphics, SAP, etc.) In the research field, works have been carried out to enhance the quality of the data to be saved and shared. Many research works on Knowledge Management have been applied to PLM approach. [7] presented a configuration-oriented product system based on knowledge management. This work was applied to made-to-order manufacturing enterprises and presented interesting results. However, this research is clearly dedicated to an industry with very specific requirements in terms of product development. [8] presented a computer-aided system enabling the designers to capitalize and share knowledge issued of preliminary tasks of a product development project. However, the results concerning the reuse of the knowledge capitalized have still to be enriched. Numerous works are carried out in the domain of product data management. Based on software development topics, these researches highlight the link between CPD and product data exchange. In order to develop this link, basic technological fields are interconnected, such as Design, Production, Prototyping, etc. This interconnection implies improvement in terms of exchange and share of data trough the use of multi heterogeneous applications

which tends to the development of Specific Product Development Platforms using neutral formats (STEP, IGES, etc.). The standards resulting from this interconnection are studied in the next section. STANDARDS OF EXCHANGE In the past decade, many researches were conducted to develop a standard for the exchange of geometry. With the development of CPD, researches were conducted to exchange product data model. STEP (Standard for the Exchange of Product data model) is the most accomplished research. STEP is an international standard of ISO (International Organization for Standardisation) referenced ISO 10303 [8]. The STEP standard aims to define a non-ambiguous, computer-interpretable representation of the data related to the product throughout its lifecycle [9]. STEP allows the implementation of consistent information systems through multiple applications and materials. This standard also proposes various means for the storage, exchange and archiving of product data in a strategy of long-term re-use. Nowadays, with the development of internet, XML-based technologies are under development to enable Product Data Exchange in a PLM context. Some of them, such as 3DXML, U3D, result from the researches of developers (Dassault Systèmes, UGS, Adobe, etc.). Other researches are also being conducted, such as ISO X3D, based on the VRML technology. This format is fully opened and presents advanced functions (NURBS, components). KNOWLEGDE REUSE Knowledge reuse becomes a key factor for reducing time, cost and flaws during Product Development activities. In the domain of CPD, knowledge reuse presents particular human and technical difficulties resulting from the lack of design methodologies and specific tools. Researches are conducted to enable knowledge reuse in CPD activities. First of all, [10] defines knowledge as ‘… the entirely of skills and abilities used by individuals for a problem solving. Knowledge relies on data and information and is always bound to persons.’ Based on this definition, further researches concentrate on the acquisition of knowledge: [11] describe an approach that involves the acquisition of raw information from the keystrokes entered by the user. This approach is clearly based on the user rather than on the data managed during the product development activities. It clearly concentrates on the activities rather than on the content of the information. In this context, it hardly proposes solutions for high level of knowledge that are not clearly entered by the user. On the opposite, [12] proposes block divisions to enable knowledge management. Six of these blocks come from the research of [10] and have been enhanced by adding two new blocks defining a control cycle. The eight blocks obtained are: - Knowledge Identification (overview of existing knowledge inside and outside of the company) - Knowledge Acquisition (company’s decision to obtain knowledge from inside and outside, such as partners, suppliers) - Knowledge Development (complement of knowledge acquisition, it symbolizes the action of knowledge creation) - Knowledge Dissemination (enables the dissemination of knowledge) - Knowledge Utilization (the main purpose of the process) - Knowledge Retention (consists in the separation of valuable knowledge from the obsolete one) - Knowledge Goals (determines basic goals in the company) - Knowledge Assessment (consists in evaluating the achievement of the basic goals and taking decisions to improve the solution adopted) [14] present a knowledge representation of data, in a collaborative development environment, that is fully independent of the platform considered. This research presents a very high level of knowledge representation and interesting issues in the development of standards of exchange in concurrent engineering environments. However, it does not consider the difficulties occurring during the exchanges between experts, in terms of semantic and data management issues. [15] present an ontological knowledge management approach methodology for enriching PLM functionalities. Based on open source alternatives, this research offers a methodology for creating, managing and reusing knowledge in Collaborative Product Development. The research is clearly set in a global PLM approach and aims to offer various solutions that are not fully dependant of the expert tasks considered. In the research presented in the paper, we concentrate on the IT-oriented factors that enable the creation and use of knowledge occurring during the interaction of Design and FEA experts, in a Collaborative Product Development Project. PROPOSITION: RULE-BASED COLLABORATIVE DESIGN

In this section, we detail a rule-based collaborative design application that enriches an existing PLM application by incorporating rule-based functionalities. In the first section, the requirements of the system are detailed. In the second section, the models of the system are developed and finally the third section presents a first application resulting from the modelisation. SECTION 1: REQUIREMENTS FOR RULE-BASED CPD Firstly, the application presented in this paper has to fulfil the basic requirements of a Collaborative Product Development System. These requirements are: - structuring of product data - management of product evolution - management of data access through security control - management of processes - management of project teams and roles - visualization of product. These requirements are ensured by the use of an existing PLM application. Secondly, the application presented in this paper offers functionalities for exchanging infromation between expert phases of the design through the PLM Aplpication. The expert phases concerned are the design phase and the FEA phase. The requirements regarding this aspect are: - offering an access to the parameters driving the CAD into the PLM - offering an access to the parameters driving the FEA into the PLM - managing rules for enabling the recomputing of FEA when CAD parameters are modified SECTION 2: MODELISATION PLM aims to offer a centralized product data structure to assist product development teams. This product data structure is developed for enabling the exchange with various software including, Project Management Applications, Communication Facilities and Expert Applications. In this organization, the PLM function is to present multi views of the data and to ensure security access and storage. Then a standard PLM organization can be understood as a centralized network as presented in the Figure 1. This centralized network makes difficult the link between expert activities of the global product development process. These functionalities do not take into account the specificity of the expert tasks and tend to amplify the number of routine tasks. In this section, we present a protocol for exchanging information between the functional requirements clarification and preliminary design tasks.

Detailed Design Preliminary Design

Bench marketing

Industrial Design

PLM

Recycling

Numerical Simulation

Prototyping Manufacture

Figure 1 : centralized network of a PLM Application

Existing CAD Systems enable the use of constraints and rules for controling topological attributes of features and parts. The constraints modify the characteristic of the parts while the rules control the validity of the result. These constraints and rules can be either set in the CAD environment or can come from another source

(databases, text, html, etc.). In our case, the extension of the use of rules is proposed in order to identify and use parameters that facilitate FEA integration into a PLM Application. In this section, we present the modelisation of the system through the use of UML diagrams. We present also the XML format developed for sharing parameters and rules into the PLM application. The system developed enables: • The enrichment of the data stored in the PLM by enhancing the relevance of the ttributes describing the database meta-classes • The automation of basic updates on the design resulting from modification of the requirements data. UML specification of the system The system has been developed using UML. The first step of the development consists in the specification of the use case and sequence diagrams. The Figure 2 illustrates the basic use case: the interaction between the developed system and the user. CAD parameters and relations are created in the CAD system and are shown in the PLM. The parameters and relations are transferred into the CAD system by the PLM: this exchange is carried out in a batch ode and are updated directly when the CAD model is opened. PLM and CAD integration using the relevant parameter engine Storing Functinal Analysis Results

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** Functional Analysis Actor

PLM Application

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Linking Functional & CAD parameters *

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*

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* *

CAD Application

Storing Design Models *

Designer

Figure 2: use case diagram of the system

The Figure 3 presents a sequence diagram of the system developed. The achievement of a designer basic task is done according to the system. From the classical interaction with the PLM applications to the connection between the requirements data and CAD parameters, this diagram presents the successive operations that occur during the design tasks. First, the designer receives the requirements by querying the PLM Database. The requirements are automatically integrated to a new CAD file. Second, the designer performs his task and provides a parameterized CAD model based on these requirements. The end of the sequence depends from this task: the parameterized CAD model has to be robust enough in order to support all design changes. This robustness is largely depending on the design expertise and on the quality of the 3D-modeling. In this context, modelling methodologies has to be provided and best practises to be taken into account by the designers. Third, the CAD data are stored in the PLM Database and the link with parameters issued from functional requirements clarification is provided using an XML file transfer. PLM System

Relevant Parameter Engine

CAD System

Design Expert Finding New Task

Requirements

Retrieving Requirements For New Task

Design Parametrized Product Relevant Data CAD Data Relvant Data Resulting from the Parametrized Design

Figure 3: sequence diagram of the system

Description of the XML file transfer

XML technology has been used to provide integration with existing PLM and to simplify the link with CAD system through the use of Web technologies. The link between the CAD file and the PLM is set using the PLM functionalities (Check-in; Ckeck-out; Maturity; Lifecycles) and an XML file enabling the storage of valuable parameters into the PLM. These parameters are chosen by the CAD expert during the Check-in phase. This file is updated when a change occurs in the PLM or in the CAD File. Adding to that, XML Document Type Declaration (DTD) enables the declaration of new blocks. This characteristic provides efficient solutions that can be easily enriched with further version of the tool. The XML file lists the parameters and values issued from the requirements clarification of the product to be designed. Each parameter is described in the file and documentation is provided to support the designer in his /her task. SECTION 3: APPLICATION In this section, we present the first prototype developed using the modelisation presented in section 2. This prototype enables the link between CAD expert data and others expert phases trough the use of a PLM application. The CAD application used in the prototype is CATIA V5R14 and the PLM Application is ENOVIA Virtual Product Manager (VPM). The user interface available in the CAD is presented on Figure 4. It offers functionalities for exporting parameters and rules regarding a specific XML format into VPM. The XML format respect the format developed during the modelisation phase. An example of the XML file is shown on Figure 5.

Figure 4: user interface included into the CAD application

56 52,6227867640013 63,4666666666667 46,6666666666667 5 3,73333333333333 20 20 20 20 Figure 5: xml example of the description of a single parameter attributes

CONCLUSION The research presented in this paper is based on the cross-domain of CPD and Knowledge Reuse researches. In this context, we focused on prior researches conducted in the domains of CPD, Knowledge Management and exchanges between expert applications, which tend to focus on standard of exchange technologies. Based on this synthesis, we developed, in a PLM context, set of rules defined to enable knowledge reuse and new specification for specific data transfer protocols. These protocols included the basic requirements for CPD and methodologies for improving CPD using rule-based applications. These developments were presented using the customisation of an existing PLM Application. REFERENCES [1] Rodriguez K., Al-Shaab A., Knowledge web-based system architecture for collaborative product development, Computers In Industry, 56, 2005, p. 125-140. [2] Gomes, S. & Sagot, J.C., A concurrent engineering experience based on a cooperative and object oriented design methodology, Best papers book, 3rd International Conference on Integrated Design and Manufacturing in Mechanical Engineering, Kluwer Academics Publisher, 2002, pp. 11-18. [3] Eynard, B. et al. (2005), Web based Collaborative Engineering Support System: Applications in Mechanical Design and Structural Analysis, Concurrent Engineering: Research & Applications, Vol. 13, 2005, N°2. [4] Rodgers, P., Caldwell, N.H., Clarkson, P.J., Huxor, A., (2001), The management of concept design knowledge in modern product organizations, International Journal of Computer Integrated Manufacturing, Vol. 14 (1), 2001, pp. 108-115. [5] Abrahamson, S., Wallace, D., Senin, N., Sferro, P., (2000), Integrated design in a service marketplace, Computer Aided Design, Vol. 32, 2000, pp. 97–107. [6] Liu, D.T. & Xu, X.W., (2001), A review of web-based product data management systems, Computer in Industry, Vol. 44, N°3, 2001, pp.251-262. [7] Zhang, J.S., Wang, Q.F., Wan, L. et al., (2005), Configuration-oriented product modelling and knowledge management for made-to-order manufacturing enterprises, International Journal of Advanced Manufacturing Technology, Vol. 25, 2005, pp 41-52. [8] ISO 10303-1 (1994) ‘STEP - Part 1: Overview and fundamental principles’.

[9] Yoshioka, M., Umeda, Y. et al., (2004), Physical concept ontology for the knowledge intensive engineering framework, Advanced Engineering Informatics, 2004, Vol. 18, pp. 95-113. [10] Probst, G., Raub, S., Romhardt, K., (1999), Wissen managen: wie unternehmen ihre wertvollste resource optimal nutzen, 3rd Ed. Frankfurt/Main FAZ. [11] Seshasai, S., Gupta, A., Kumar, A., (2004), An integrated and collaborative framework for business design: A knowledge engineering approach, Data & Knowledge Engineering. [12] Anderl, R., Thel, M., Platt, K., (2005), PDM-Systems as Organisational Knowledge Base, Proceedings of ProSTEP Ivip Science Days, Darmstadt, 2005. [14] Zhou, S., Peng, Z., Yarlagadda, P.K.D.V., A complete solution for neutral knowledge representation within collaborative product development environment, International Journal of Advanced Manufacturing Technology 25 (2005), pp 761-771. [15] Aziz, H., Gao, J., Maropoulos, P., Cheung, W.M., Open standard, open source and peer-to-peer tools and methods for collaborative product development, Computers In Industry 56 (2005), pp 260-271.