Niek Du Preez

Nicolas Perry

Alexandre Candlot

Alain Bernard

Wilhelm Uys

Louis Louw

Customised high-value document generation

Keywords: Methodology, Knowledge, Integration

Contributions of different experts to innovation projects improve enterprise value, captured in documents. A subset of them is the centre of expert constraint convergence. Their production needs to be tailored case by case. Documents are very often considered as knowledge transcription. As the base of a structured knowledge-based information environment, this paper presents a global approach that helps knowledgeintegration tool deployment. Two contrasting examples indicate how fundamental understanding of domain infrastructure contributes to a more coherent architecture of knowledge-based information environments. The first example is related to insurance services and uses roadmap and ontology to redefine a more coherent insurance contracting relation. The second example focuses on aircraft manufacturing and develops through diagram modelling, application specifications for process plan definition.

INTRODUCTION 1.Documentation Complexity

Lean extended enterprise and build-to-order induce better integration of PLM activities that go through computer aided systems and knowledge-based information environments [1]. This change of landmarks from physical document to electronics claims to redefine information support functionalities [START_REF] Ha | Managing design knowledge : active document system[END_REF]. Specifications or constraints are usually transmitted from one expert to the other in a global convergence [START_REF] Candlot | Synergy and Knowledge in an Innovative Project between Academia and Industry[END_REF]. The differences between their competencies limit the global understanding of problems. Computer integration in the expertise chain aims to optimise this kind of relations and thus the use of enterprise knowledge. The number of different enterprise concepts and complexities caused by different interpretations of these concepts encourages enterprises to standardise concepts and formalise behaviours. These efforts build re-usable and adaptable platforms and imply deep business architecture redeployments [START_REF] Midler | L'Auto qui n'existait pas[END_REF]. The rapidly changing environment requires convenient collaboration knowledge integration tools [START_REF] Rozenfeld | An Architecture for Shared Management of Explicit Knowledge Applied to Product Development Processes[END_REF] and interoperability between different information sources [START_REF] Sheth | Changing Focus on Interoperability in Information Systems: From System, Syntax, Structure to Semantics[END_REF]. The main difficulty encountered is to control the complexity of information quantity and informality. A reduction of the workstructure diversity helps in this regard to optimise the information efficiency. Seen from the process of collaborative document writing, it is hard to guarantee the consistency of the document's subject. The contents of shared documents may deal with many subjects and fields, and every collaborator would compose the text by its own understanding, different from other's because of different knowledge backgrounds. As a result the subject of the shared documents will be inconsistent among many copies. Furthermore, the communications between collaborative systems, the systems and environments will also influence the consistency of the subject. An approach focussing on the semantic and syntax distinction can help to resolve the consistency problems involved in collaborative writing [START_REF] Jianshe | Using Ontology to Solve the Consistency Problems in Collaborative Writing[END_REF].

Project Context

This work is part of a collaboration project between two research teams supported by NRF in South Africa and CNRS in France. It aims at the identification of possible synergy around performance indicators for knowledge management improvement This collaboration starts from a global observation. When benefits from productivity optimisation become harder to obtain, the market expectancies are changing faster. Enterprises have to analyse and control their core competencies to react efficiently to this new challenge. In the following sections, two different approaches on two different application fields prove the interest of a global methodology for the creation of information consolidation tools in order to build structured knowledge-based information environments. This paper presents a three-phased methodology to optimise and ensure coherent enterprise documentation: 1. At first must be identified the fundamental elements of the structure. It corresponds to the Infrastructure Definition Phase. 2. Relationships between these elements are then identified, and the elements are deployed in a coherent manner to optimise their efficiency. It is the Architecture Phase. 3. The third phase is document generation by a validated knowledge-based application

KNOWLEDGE BASED COMPLEX DOCUMENT GENERATION 2.1 Understand Infrastructure

The enterprise Infrastructure is constituted of elementary concepts that can be classed among process, products, resources and external effects [START_REF] Labrousse | Generic FBS concept for Process/Product/Resource integration[END_REF]. These concepts enable the specification of all enterprise objects relating to three different points of view: functional, behavioural and structural (FBS) [START_REF] Labrousse | Enterprise processes traceability based on a FBS approach[END_REF]. Their boundaries can be retrieved through the perception ability of stakeholders [START_REF] Cassin | Vocabulaire Européen des Philosophies[END_REF]. Each person naturally does this division, but the formalisation of a common understanding is harder to accomplish. The reason is that knowledge and meaning can't be externalised from humans to computers [START_REF] Searle | Minds, Brains, and Programs[END_REF] or other documents. Meaning contained in representations has to be internally rebuilt by users [START_REF] Cassin | Vocabulaire Européen des Philosophies[END_REF]. Documents are considered as the inscription of knowledge and the problem is to analyse and propose structuration concepts as a base for their management. Ontology is one of the possible ways to achieve this goal. Research on ontology [START_REF] Guarino | Formal Ontology, Conceptual Analysis and Knowledge Representation[END_REF] seeks to provide enterprises with concept definition and management tools [START_REF] Troncy | DOE : une mise en oeuvre d'une méthode de structuration différentielle pour les ontologies[END_REF] The aim of this first phase is to differentiate concepts. The analysis of their relationship is part of a second phase focusing on Architecture. Concepts "behave" differently according to their context. The modelling of this structure and the analysis of its possible evolution constitute the Architecture phase.

Construct the Architecture

The maturity of the Infrastructure knowledge leads to a restricted number of concepts. They are more relevant and meaningful for defining the specifics of the studied domain. They are usually formed by a general name (corresponding for example to UML Class) and a limited numbered of typological instances (corresponding to UML Object). The sum of their behaviour constitutes an as-is platform from which all the business outputs are derived. Usually the platform is build informally according to the enterprise evolution. It raises incoherencies in concept levels or typology definitions. Concretely it can be illustrated by a misuse of a machine (unclear relationship between a process and a resource), an inefficient procedure (confusion in processes), or an unsatisfactory product (unconsidered external effects, badly defined core product concepts). In order to optimise platform efficiency, the roles of the Architecture phase can be defined as follow:

 Ensure the coherency between concepts  Optimise relationships and build working environments  Evaluate model maturity and complexity reduction  Define a coherent integration method of knowledge in final products The two following examples highlight how a domain Infrastructure and Architecture form an enterprise management Infrastructure. This global as-is state can be then redeployed through an enterprise management Architecture to ensure a better use of enterprise knowledge.

EXAMPLE ANALYSIS IN INSURANCE INDUSTRY DOMAIN

This example focuses on complex contract documentation found in insurance companies. It illustrates how the methodology introduced in this paper helped to analyse and improve the current Master Contract between the insurance company and its policyholders by first getting a good understanding of the current contract and its impact on the enterprise infrastructure. From this, improvements to the existing enterprise infrastructure could be made, and a new improved contract could be generated. This contract can then become a specification base for a CRM tool.

Context presentation

A given insurance company offers health cover, in certain categories, to its clients in the form of policies. A Master Contract governs all benefits and requirements between the insurance company and its policyholders. This contract is complex in nature mainly because of the use of complicated, inconsistent terminology, non-optimal grouping of related concepts, complicated product/business rule descriptions, ambiguous formulation, etc. Many of these problems exist because different experts, from different domains within the company, are required to work on the same contract document. Matters are further complicated because experts don't always have a shared understanding, and no standard, agreed-upon terminology exists. Historically the contract also has evolved over a period of more than 60 years, adding to its Infrastructure intricateness. In the event of a claim, the contract may in some cases be interpreted differently by the client and the insurer, leading to disputes between the two parties. Disputes damage the client-insurer relationship and may lead to extensive legal expenses for both parties. IT systems are used to calculate premiums, cover, claim payments, subject to certain rules and requirements. The complexity manifesting in the contract, also leads to complexity in the IT systems. In order to configure the IT systems, the contract must be interpreted. Ambiguous interpretations may lead to inconsistencies between the contractual terms and the IT systems, creating a legal risk to the company. In order to effectively, manage and reduce these complexities, a three-layered approach is followed. 1. Model and analyse contract paragraphs 2. Concepts are extracted from these contract paragraphs and relationships are established to other enterprise concepts The analysis of the paragraphs and the extraction of the paragraph concepts therefore correspond to understanding of the Domain Infrastructure. The Domain Architecture is then constructed by defining the relationships between these concepts and an enterprise ontology. This leads to a better understanding of the enterprise infrastructure (As-Is state), from which improvements can be made through an enterprise architecture (To-Be state). The process is summarised in Figure 2.

Contract infrastructure definition phase

Paragraphs are the basic building blocks of a document. In a legal document, paragraphs usually represent contract clauses that contain Role-players, Documents, Rules (Requirements / Restrictions), Events and Procedures. Because of non-coherent concepts used in paragraphs, complexities arise that lead to misinterpretation and misunderstanding. As a first step to understand the existing contract infrastructure, paragraphs in the contract are analysed on a business process level by mapping flows within the paragraphs using a process-modelling tool called Moogo. This gives a visual representation of the interactions between the abovementioned elements in the paragraph and helps to overcome the interpretation limitations caused by natural language. Furthermore, interactions also exist between different paragraphs. Mapping the interactions in a mindmap format can highlight these interdependencies. This contributes to a better understanding of the influences that possible changes to contract paragraphs may have on other contract paragraphs. This understanding of the content and intent of paragraphs is an important first step in analysing complex documents for simplification.

Contract and enterprise architecture development phase

The next step is to extract specific concepts from these contract paragraphs and to establish relationships to other enterprise concepts contained in overall enterprise ontology. The impact of these paragraph concepts on enterprise concepts such as organisational structure, business processes, products, IT systems, the legal and legislative environment and allianced enterprises, etc., are therefore established and captured in an ontology. An ontology visualisation tool is used to portray various concepts and the relationships that hold among them. The resulting ontology helps to identify incoherencies in concept levels or typology definitions, as well as indicating what enterprise concepts are impacted by the Master Contract. In order to get a more detailed understanding of the impact on the enterprise architecture as a whole, the "as-is" state of the enterprise can be modelled using appropriate modelling tools as well as an enterprise modelling architecture (Modified PERA [16] in this case). Improvements in the business functions, information systems architecture, organisational architecture and hardware architecture can subsequently be developed using a comprehensive enterprise design life cycle architecture, thereby creating a required "to-be" state of the enterprise. Figure 3 presents an example of the PERA Master Plan architecture that serve as a roadmap for the improvement effort. An enterprise-wide innovation management software tool called EDEN™ supports this improvement effort. EDEN™ is a software environment, which provides high-level control over change-projects, supporting a multi-disciplinary team through a predefined roadmap structure [17]. It contains different enterprise reference architectures such as an enterprise life cycle, product life cycle, technology life cycle, and master plan for change projects that serves as a common reference framework and creating a unified understanding of the enterprise infrastructure. Good practice information is shared and experience and knowledge is captured within the EDEN™ environment. It ensures clarity, uniformity and coherency between different experts working on the same project. Figure 4 presents an example of the EDEN™ user interface.

Improved Contract Generation

In order to decrease the complexity and ambiguity of the Master Contract, it was necessary to firstly understand the contract, and secondly its impact on the enterprise as a whole. The root causes of the contract's complexity and ambiguity lies not only in the contract itself, but also in the larger enterprise in the form of unclear/inconsistent business processes, complex product structures, ambiguous decision-making authorities and structures, It was therefore first required to improve the enterprise structure, and update the relevant ontology before an improved Master Contract could be generated. The enterprise-wide innovation management tool EDEN™ was used to support the collaborative modelling, improvement, and document generation processes. To summarise, ontology first help creating the as-is picture of the enterprise, giving an understanding of the enterprise, highlighting its incoherencies and guiding the to-be improvements formulation. In a second phase, the to-be changes to the enterprise have been implemented. Consequently, the first ontology had to be updated in order to incorporate the new evolutions. EDEN™ and roadmap methodology becomes a used common reference for developing a new, improved, simplified, coherent Master Contract that leads to more secured specifications of CRM tools.

EXAMPLE ANALYSIS IN AIRCRAFT MANUFACTURING DOMAIN 4.1 Definition of the couple Product / Process

In the world today, companies' computerization forces to assume that computer aided systems support design and manufacturing preparation phases [17]. Even if a global integration of the whole product and process life cycle is deployed, the harmonisation of the semantics associated to each expertise included in the life cycle remains difficult. When this integration issue isn't necessary for the enterprise, as in this example, several conceptual worlds keep on co-exist and forces multiple expert reinterpretations. The following sections illustrate this case through the experience of an aircraft manufacturer. In a partnership with CAD/CAM development leader, five laboratories and a government organisation, the study of the possible integration of Manufacturing-Preparation Decision Process leaded to a Research Project supported by the French Ministry of Industry [19]. It aims at the specification and development of a knowledge-based engineering tool to help the definition of process plan for small-size highspecificity production batches. Partner number and diversity have required a common reference to refine specifications from the expressed needs of the aircraft manufacturer to the final knowledge-based engineering tool. The process plan is the complex document considered here. It can be seen as the output of the KBE tool. This tool is specified either by the sum of diagrams (graphical representation) or by the sum of objects and their ties (informatics representation). Their evolution depends on two knowledge axes: the project maturity and the refinement of domain knowledge.

Project Infrastructure definition phase

Three main kinds of expertise were grouped on this project: aircraft manufacturing knowledge, scientific optimisation methods and CAD software programming. Each of them associates its own understanding to the following conceptual worlds: design specification, geometry and process capabilities.

The combination of these expertises (used for the project) and conceptual worlds (illustrating expertises contained in the life cycle) formed an implicit conceptual corpus. The first task of the Infrastructure Phase is to systematically identify them through documents, presentations and meetings. The justification of this work lies in the need of visibility and understanding. It creates an IS ontology [START_REF] Zuniga | Ontology: Its Transformation From Philosophy to Information Systems[END_REF] that represent the inter-subjectivity of stakeholders, preparing a coherent referring base to build the final KBE application. A modelling tool, MEGA, helps to perform this systematic exploration. UML-like Activity diagrams and UML Class diagrams [21] [START_REF] Bernard | Fundamental concepts of product/technology/process informational integration for process modeling and process planning[END_REF] have been used and are presented on Figure 5 and Figure 6. The interest of these formalisms is that they propose a strong common syntax but let people free to rebuild their own semantic interpretation of meta-models. To keep advantage of the flexibility, this freedom nevertheless implies a clear common definition of this semantic before starting to model [START_REF] Gruber | Toward Principles for the Design of Ontologies Used fo Knowledge Sharing, International Workshop on Ontology[END_REF]. Each rework of all the models that can regularly occur when deep changes have been highlighted is the occasion to renegotiate the semantic interpretation. These reworks are significant leaps to maturity. During the project development, three principal phases appeared:  Brainstorming phase: all partners propose the objects they feel they need for their part of the work. The separation of tasks is difficult and processes are often over detailed and over constrained. The number of concepts and processes rapidly increases.

 Homogeneity Phase: the knowledge on the existing software model increases and brainstormed concepts are progressively replaced by corresponding elements of the already-deployed models (Industrially or scientifically).

 Refinement phase: The tasks on processes are better distributed and are more homogeneous. The spine of the data model is progressively defined. Models are simplified by the identification of main concepts that are kept for rapid communication in the project team. The remaining items are semantically more relevant and coherent together.

Project Architecture constitution

As main items has been identified, the specification maturity process continues in detailing methods that make them interacting. In the presented industrial case, the specifications of the Architecture can be summed up to a need for a link between geometry and resources and a resolution of constraints problems The central place of knowledge capitalisation through databases orientated the solution to an integration of Tools, possible manufacturing Sequences and classified Entities in one main database called OSE (French acronym for Tool, Sequence and Entities [START_REF]Object Management Group, OMG Unified Modeling Language Specification[END_REF] they are the high-value project-infrastructure concepts). For the constraint convergence of these semantically different items, a class system has been added to help the aggregation of all elements. The new Infrastructure organisation is presented on Figure 8.

Complex Document

Thus, for each new part considered, it becomes possible to first automatically identify the manufacturability of geometrical entities and then prepare the skeleton of the process plan by an organisation of sequences.

Another procedure helps to define the set-ups by calculations of accessibility directions. It hasn't been described here as on the contrary of the example, it involves homogenous mathematical data. With the help of these tools, the CAD document can rapidly be transformed in a CAM document, the expert concentrating his efforts only on difficult points. At the end of the pre-competitive phase of the development project, the expected gain is a ten factor. The resulting tool must still be completely deployed and validated by the industrialisation phase. Other fields of application could expect benefits from modelling processes followed here. Cost optimisation in microelectronics components is prospected and a similar approach is deployed in this new context.

COMPARISON OF EXAMPLES

The conceptual similarities between these two very different application examples reminded on Table 1 encourage both teams to structure their work in a similar methodological approach. Next works should focus on how to monitor the global data evolution. Moreover the main advantage felt by the teams is the distinction between project and domain elements that is revealed in the need of clearly specifying the project syntaxes for a better construction of the domain semantics. The realisation of this problem is eased by the introduction of the Infrastructure and Architecture phases.

Table 2: General to specific phase identification

CONCLUDING REMARKS

In a nutshell, this paper proposes a methodology to refine unorganised information complexity to semantically enriched relevant concepts. This reduction of the work structure complexity and heterogeneity helps to optimise the complex document generation by creating more coherent applications or work environments. The maturity of knowledge contained in these structures contributes to a better agility towards output expectations. The introduced distinctions between Infrastructure and Architecture in one hand and Domain and Project in the other induce de facto an awareness of stakeholders on their position on a knowledge refinement scale. It avoids confusions in concepts considerations and allows the identification of global project risk. The two specific contributions open ways to deploy these principles in different activity domains. The separation between methodology and methods comforts a step further the possible agility that today's enterprise project culture may require.

[1] M. Thannhuber, M. M.

  [START_REF] Bachimont | Semantic Commitment for Designing Ontologies: a Proposal[END_REF] [15]. The common main steps are:  Domain limit definition  Manual or Automatic Corpus Analysis  Concept extraction and organisation

Figure 1 :

 1 Figure 1: Two levels of Infrastructure and Architecture.

  in an overall enterprise ontology. 3. Modelling of As-Is enterprise infrastructure, and developing of To-Be improvements.

Figure 2 :

 2 Figure 2 : Master Contract Improvement Process.

Figure 3 :

 3 Figure 3: PERA Master Plan Roadmap.

Figure 4 :

 4 Figure 4: EDEN User Interface.To summarise, ontology first help creating the as-is picture of the enterprise, giving an understanding of the enterprise, highlighting its incoherencies and guiding the to-be improvements formulation. In a second phase, the to-be changes to the enterprise have been implemented. Consequently, the first ontology had to be updated in order to incorporate the new evolutions. EDEN™ and roadmap methodology becomes a used common reference for developing a new, improved, simplified, coherent Master Contract that leads to more secured specifications of CRM tools.

Figure 5 :

 5 Figure 5: AS-IS Infrastructure Simplified Class Diagram.

Figure 6 :

 6 Figure 6: Part of the Domain Activity Diagram.

Figure 7 :

 7 Figure 7: Concept Validation with Sequence Diagram.

Figure 8 :

 8 Figure 8: OSE Architecture Organisation.

Figure 9 :

 9 Figure 9: OSE Architecture Deployment.

Table 1 :

 1 Example-Context ComparisonNaturally similar kinds of problematic are encountered, implying the search for common knowledge-based methods to solve them. It indicated that completely different tools (EDEN and Roadmap towards MEGA and UML diagrams) have deep similar concerns, i.e. to ensure coherency, consistency and a unified understanding in multi-faceted project teams. The integration of both methodological aspects and technical solutions leads to a skeleton strategy reusable for further identical problems. The main experience outputs are summarised in Table2. In this process of specification refinement for a final complex document, strengths and weaknesses appear at the same stages in the two examples. The first drawback is that a relevant collection of terms is difficult to create. In both examples this task is manually performed. Informatics research works on algorithms to automatically analyse a document corpus in order to create a first cut of a structuring ontology. The other difficulty lies in compiling statistical data in relevant indicators. The creation of a global methodology gives a better understanding of what should be monitored. It can be maturity phases or the respect of the methodological principles highlighted here. The Architecture phase goals are thus valuable hints for such indicators.


Frank Walter Jaekel
email: frank-walter.jaekel@ipk.fhg.de

Nicolas Perry
email: nicolas.perry@irccyn.ec-nantes.fr

Cristina Campos
email: camposc@uji.es

Kai Mertins
email: kai.mertins@ipk.fhg.de

Ricardo Chalmeta
email: rchalmet@uji.es

Interoperability Supported by Enterprise Modelling

The application of enterprise modelling supports the common understanding of the enterprise business processes in the company and across companies. To assure a correct cooperation between two or more entities it is mandatory to build an appropriate model of them. This can lead to a stronger amplification of all the cross-interface activities between the entities. Enterprise models illustrate the organisational business aspects as a prerequisite for the successful technical integration of IT systems or their configurations. If an IT system is not accepted because its usefulness is not transparent to the staff members, then it quickly loses its value due to erroneous or incomplete input and insufficient maintenance. This at the end results in investment losses. The paper exemplifies the strengths, values, limitations and gaps of the application of enterprise modelling to support interoperability between companies. It illustrates a proposal for a common enterprise-modelling framework. This framework is presented in terms of problems to face and knowledge based methodological approach to help solving them. A specific application demonstrates enterprise modelling and the synchronisation between the models as prerequisite for the successful design of Virtual Enterprises.

Introduction

The implementation of information systems and new organisational structures into and between companies requires discussions between different stakeholders of the enterprise (e.g. process design experts, managers, process owners, IT experts). Therefore the modelling of enterprise processes including related information systems and organisational units is an essential step in the process of changing and improving enterprise structures. The target is to achieve a common understanding of requirements of a new system. This is true for big companies as well as for small and medium size enterprises (SME). Furthermore the enterprise modelling bridges the gap in transforming process organisation of an enterprise and the processes implemented within the IT systems. The complexity of the modelling approach increases if used across enterprise networks.

The modelling of enterprise business processes is growingly becoming a well known technique especially within big companies. Now also SMEs are forced by their customers to increase the transparency of their processes. Moreover, the need of IT support such as ERP systems increases for SMEs. The establishment of information systems within a company is a difficult task. Various applications of IT systems are not efficient because of a lacking acceptance on the user side and of deficits between the real process organisation of the enterprise and the support of the IT systems.

Experiences from industrial projects illustrate that companies which buy an IT system without a clear strategy for enterprise business process improvement and little knowledge regarding the organisational effects often fail in applying the software. Therefore, big companies as well as SMEs require a modelling approach to create an enterprise (business) process blue print for a successful implementation of IT systems. The model is oriented to and across process owners or stakeholders of operational and management departments. Consequently the description of the process structure and its relations to different resources such as organisational units, IT infrastructure, information exchange, etc. has to be easily understandable.

Enterprise modelling concerns awareness of enterprise cultural particularities. The goal is to answer the question: 'How to make different enterprise models interoperable made from different modelling methodologies languages and metamodels, modelling background and environment?'.

The topic is covered by the European INTEROP [START_REF]INTEROP: Interoperability Research for Networked Enterprises Applications and Software NoE[END_REF] Network of Excellence concerned with inter-operability research for networked enterprises applications and software, its goals, rationale and early results and by the European integrated project ATHENA [START_REF]ATHENA: Advanced Technologies for Interoperability of Heterogeneous Enterprise Networks and their Applications) Project[END_REF](Advanced Technologies for Interoperability of Heterogeneous Enterprise Networks and their Applications).

To address a Common Enterprise Modelling Framework definition, the first step is to establish a common base of understanding of different modelling constructs across different modelling languages that is a common modelling language such as the INTEROP UEML approach. The second step is to take into account the different ways of representing the real world within the model content, including aspects such as cultural and regional differences both in enterprise way of working but also in the way to build models, different objectives driven models and so on.

Models Across Organizations

Problems of Enterprise Modelling between Companies

In the actual situation regarding enterprise modelling several modelling methods and tools are used in enterprises (Figure 1). For example, MO 2 GO [3] supporting the integrated enterprise modelling is preferred because of a fast and easy understandable modelling method across different stakeholders. GRAI [START_REF]GRAITools: Website[END_REF]Tools are prioritised especially for modelling the decisional processes of an enterprise. ARIS [START_REF]ARIS: Architecture of Integrated Information Systems[END_REF] is popular for enterprise modelling especially in the IT domain and IT departments. METIS [START_REF] Metis | [END_REF] supports a very flexible meta modelling and therefore a good adaptation of the user wishes according the modelling constructs. The information covered by these tools is similar. Therefore, to save the investment for method training and model elaboration an exchange of the information modelled within the different tools should be provided. In the first step within INTEROP this is a topic of the Unified Enterprise Modelling Language (UEML) [START_REF] Berio | Common Enterprise Modelling Framework for Distributed Organisations[END_REF]. The problem of dealing with different models does not only depend on the modelling language. The same issue might be defined in two different models with different terms (e.g. Lead engineer / Project engineer) but at the same time in a third model these terms may have another meaning. Instead of the modelling language the natural language might be hindered by an information exchange and cooperated work on the models because a translation into an interlingua e.g. English might result in misinterpretations without having a common ontology support. The perspective between two models dealing with the same information might be different e.g. order processing or product process-ing concerning the external interfaces of an enterprise. The structuring of the processes as well as the design of the process chains might be dissimilar e.g. the two processes 'Preparation' and 'Send quotation' could appear in another model just the process 'Enquiry processing' (Figure 2). These are some examples of the problems under consideration in the INTEROP work around synchronisation of distributed enterprise models. Further problems arise concerning the management of such distributed enterprise models. An enterprise model associated with different other models requires clear procedures of how to perform changes [START_REF]SPIDER-WIN: Supply Information Dynamic Exchange and ContRol by Webbased Interaction Network[END_REF]. The intension of the paper is to motivate enterprise modelling supporting interoperability. More information regarding requirements and state of the art of enterprise modelling in the context of interoperability can be found in [START_REF] Knothe | UEML Public Deliverable D2[END_REF] [10] [11]

Values of Enterprise Modelling

The application of enterprise modelling supports the common understanding of the enterprise business processes in the company and across companies. The company is supported to succeed in reducing the throughput times, in improving the process quality, in reducing costs and therefore in improving the customer satisfaction and competitiveness. Enterprise modelling should be the basis of the information system planning process. The use of enterprise modelling for supporting and achieving company interoperability has different motivations, for example:

-Identification of companies' potentials for acting within different cooperation. -Enabling companies to participate within collaborations through gathering the required data from the companies. -Clarification of the connection between the operating processes of the companies and the required IT support through the illustration of additional operations. -Model supported coordination, composition and synchronisation of organisation structures and business processes between the companies, especially identification of the aspects which support or, what is even more important, inhibit interoperability.

Distributed Project Management and Models

Lean extended enterprise and build-to-order induce better integration of Product Lifecycle Management activities that go through computer-aided systems and knowledge-based information environments. This change of landmarks from physical documents to electronics claims to redefine information support functionalities and knowledge-based tools to support worldwide project collaboration. Moreover, extended enterprises and collaborative projects have to analyse and control their core competencies to react efficiently to the market challenges (time to market, variability of products..). The number of different enterprise concepts and complexities caused by different interpretations of these concepts encourages enterprises to standardise concepts and formalise behaviour. These efforts build re-usable and adaptable platforms and imply deep business architecture redeployments. The rapidly changing environment requires convenient collaboration and knowledge integration tools, and interoperability between different information sources. As a result, Knowledge Management has become a key facilitator in improving the global competitiveness of companies. As competitive drivers are forcing companies to innovate and change, effective knowledge management is essential to realise and also efficiently implement these changes.

To reach these goals, project management have both to integrate this expert's knowledge and the collaborative project constrains. Consequently interoperability, in terms of synchronisation problems, will occur at these two levels. We will mainly describe the first aspect assuming that a same approach can be applied for project models and alignment.

Experience feed back and method proposal

Based on experimental cases we propose knowledge based projects methodology with three phases to optimise and ensure coherent enterprise project management:

-Project infrastructure definition, defines the fundamental elements of the project (domain infrastructure). Based on a syntax/semantic approach of the project's concepts model in order to differentiate concepts. The analysis of their relationship makes the domain architecture. Concepts 'behave' differently according to their context. -Project architecture, explains the relationships between these elements and the way they are deployed (TO BE situation) in order to measure their efficiency. -Document generation, describing the knowledge-based application specification for the software developer.

Projects

Next the two projects that integrate this methodology are described.

Information consolidation tool in order to build structured knowledgebased information environments This is a French National Project [START_REF] Candlot | Deployment of an Innovative Resource Choice Method for Process Planning[END_REF], including 5 academic partners, an aircraft manufacturer (the client) and a CAD-CAM System developer, in which we experimented different aspects of the distributed model management. Clear process definition, steps deliverables and objectives, concepts and working area had to be expressed. Based on the knowledge, experience and requeriments of the end user, the academic works had to capture and formalize the knowledge, improve and strengthen it before specifying software functionalities. We aimed to address 'efficiency of experts to share knowledge', and, due to our project team structure, we had to experiment it between partners. Indeed, specifications or constraints are usually transmitted from one expert to the other in a global convergence. The differences between their competencies limit the global understanding of problems. Computer integration in the expertise chain aims to optimise this kind of relations and thus the use of enterprise knowledge. The main difficulty encountered is to control the complexity of information quantity and informality. A harmonisation of the work-structure will reinforce the efficient use and clearness of information.

Economical model integration Software developers want to unify the four software solutions they developed independently [START_REF] Perry | Integration of Cost Models in Design and Manufacturing[END_REF]. The purpose is the cost estimation (costing) or sale price determination (pricing) in the micro-electronics field. The goal is to describe a generic economic model used for the determination of the product industrial value. Each tool answers various aspects from the silicon wafer to the finished products (electronic boards, mobile phone). The expert, distributed in different structures (production plant, design offices, buyer or seller services) had to unify parts of their costs models, their calculations rules, data inputs. The complexity relies on the fact that at different phases of the product life cycle, these software are used either by an engineer, a seller or a buyer. Consequently, their own integration of the tools in their project management is very different (objectives, information truth).

In both cases, we used a project modelling methodology supported by the MOKA supporting tool PC-Pack to build common ontology from expert documentation, the modelling tool MEGA, to perform Project Knowledge mapping with a systematic exploration, UML-like activity diagrams and UML class diagrams and time model synchronisation have been used as a possible support of these models alignment. The interest of these formalisms is that they propose a strong common syntax but let people free to rebuild their own semantic interpretation of meta-models thereby ensuring the whole project evolution in coherency with the initials objectives.

In term of model synchronisation, these two examples illustrated different distributed knowledge based projects, integrating cultural, geographical differences between partners or co-contractors. The spaces / domains comparison helps to analyse the model compliance (including model coherency, bijection, mapping of concepts, Meta model definition) and determine the synchronisation needs (this is a part of the domain infrastructure definition).

The use of a common methodology based on six core concepts (Syntax/Semantic: to give shareable modelled concepts, Infrastructure/Architecture: to define concepts and their interrelationships, Domain/Project: to represent 'AS IS' and 'TO BE' situation) helps the partners to understand each other and share models, information and requirements to perform the works. It still remains the problem of the life of such a distributed project model, for instance how to integrate new final user requirements on the knowledge based tool that rely on different fields of expertise after the end of the specification phase, or how to manage the evolution of the initial project objectives (financial support reduction and technical adaptations for example).

Enterprise Modelling and Virtual Enterprises

A Virtual Enterprise is a temporary alliance of independent enterprises that come together to share resources, skills and costs, with the support of the Information and Communication Technologies, in order to better attend market opportunities. To design an efficient and flexible Virtual Enterprise that gives the appearance of being a single enterprise to customers is a very complex task [START_REF] Chalmeta | References architectures for enterprises integration[END_REF]. A Virtual Enterprise involves a great number of organizations, usually SME, that need to closely collaborate and to be in contact in order to achieve their objectives (competitiveness, better service for their clients, etc.) in this context the use of enterprise models is a key factor became successful.

Methodology for developing a virtual enterprise

In order to help the creation and management of a Virtual Enterprise, partners develop models using different Enterprise Modelling Languages and different background knowledge. These enterprise models need to be interchangeable and understandable for people involved in each enterprise and for the whole virtual enterprise. In addition, Virtual Enterprises need to update their models due to the natural evolution of business, new legal requirements, changes in the strategy of the partners, and so forth. This kind of changes can affect concepts, business, results and other aspects in enterprise models that are needed to work correctly in real time [START_REF] Chalmeta | References architectures for enterprises integration[END_REF]. Therefore synchronisation is really important in the process of setting up a Virtual Enterprise and it becomes more critical when a Virtual Enterprise is actually running.

The methodology for the virtual enterprise integration developed by IRIS group [START_REF] Chalmeta | ARDIN Extension for Virtual Enterprise Integration[END_REF] shows how to set up practices and procedures in order to integrate a virtual enterprise. This methodology proposes (1) the definition of the conceptual aspects of the virtual enterprise and of each single enterprise (mission, vision, strategy, politics, and enterprise values); (2) the redesign of the new process map (internal business processes and cross-organisational business processes that are affected by changes), according to the previously defined concepts; (3) implementation of the VE new process map.; and (4) the extension of the information system (and the technological infrastructure) to support the process map of the virtual enterprise, considering the different levels of decision and the support technology. This methodology has been applied in several projects where thee adequate use of model languages and synchronisation between these models have been critical aspects to be successful.

These four points defined by the methodology are highly supported by the use of enterprise models, and consequently members in a virtual enterprise need to collaborate and to make al their enterprise models interchangeable and moreover, interoperable and synchronized. For the successful working on and integration of a Virtual Enterprises model contents and models management is a key issue to deal with. Therefore, it is necessary to establish the condition and the bases for good enterprise enterprise model management and synchronization.

Needs for Enterprise Modelling in Virtual Enterprises

The synchronization and management of enterprise models in a Virtual Enterprise is required under several aspects (e.g. model data, responsibilities, motivation, knowledge, configuration, social aspects etc.). The connection of different and distinct enterprise models is not limited to 'technical' or modelling language problems because, for instance, the same 'enterprise process' modelled with the same modelling language under the same objectives and requirements may differ whenever modelled by different persons.

As it is mentioned in this paper several modelling methods and tools are used in enterprises, and the application of these tools and models helps to common understanding. The same necessities analysed for enterprise interoperability can be found in the integration of a Virtual Enterprise and the same solutions must be taken into account. The application of the methodology developed by IRIS group demonstrates that the correct use of models is essential integration of a Virtual Enterprise.

Clear procedures stating how to manage and synchronize such models, templates and reference models, use of reference ontologies, training about models use and guidelines for modelling processes will help to increase the acceptance, use and results of enterprise models in the developing and management of a Virtual Enterprise and consequently improves the interoperability of all of its partners.

Conclusions

The reflections above illustrate the need of enterprise modelling to achieve and support interoperability between organisations. The INTEROP approach of the synchronisation and management of distributed enterprise models focuses on the organisational aspects of such models e.g. the common understanding regarding modelling structures or terms given to modelling elements to express the model content [START_REF] Berio | Common Enterprise Modelling Framework for Distributed Organisations[END_REF]. The INTEROP reference cases [START_REF] Jaekel | INTEROP Public Deliverable D12.2[END_REF]illustrate the advantage, needs and requirements for enterprise modelling regarding interoperability as well. Most of the reference casess started with a modelling phase introducing different tools and methodologies. It also illustrates that there is not any general procedure applied and the models depend on how the organisation provides the modelling activities. Moreover, the involvement of the enterprise stakeholders is different. Under these circumstances one can imagine the problem of a company (e.g. a SME supplier) which has to participate into different co-operations (e.g.Virtual Enterprises) and has to be compliant with the other enterprise models. First of all, the modelling language might be considered. The solution could be using the INTEROP unified enterprise modelling language (UEML) approach [START_REF] Berio | Deliverable 3.1. the UEML Project[END_REF] [START_REF] Berio | Supporting Enterprise Integration Through a Unified Enterprise Modelling Language[END_REF]. But afterwards the content of the model needs to be related to other models (structures, terms, etc.). Moreover, for achieving both compatibilities in the language and in the content (modelled information), the management of the decentralised models is required. What about changes within the model of the SME? Should they be reflected, directly, in all network models in which the SME participates? What are the results and implications of such changes?

Organizations develop models using different languages and different background knowledge. In order to achieve enterprise interoperability, it is necessary that these models will be interchangeable and comprehensible for people involved in the organization processes. The possibility of different companies to cooperate generates the necessity for models to be connected in a dynamic way. Changes in one of the models of an enterprise can affect processes, decisions and important aspects on the side of other partners. Therefore, synchronization is necessary among models from different enterprises in order to deal with changes, evolution and different views. This is a critical aspect (when models represent enterprise processes, information, organizational structures, products or decisions) for those who are closely connected to the same supply chain or to extended or virtual enterprises. methods have to be elaborated in order to support the model synchronisation and the decentralised usage of these models.

Fig. 1 .

 1 Fig. 1. Methods and Tools.

Fig. 2 .

 2 Fig. 2. Same modelling language but different understandings.

Acknowledgments

The presented research activities are partially supported by the European Network of Excellence IST-508011 'Interoperability Research for Networked Enterprises Applications and Software' INTEROP [1] and by CICYT DPI2003-02515.


Alain Bernard

N Perry

Fundamental concepts of product/technology/process informational integration for process modelling and process planning

Keywords: design, production, integration, development of products and systems

Fundamental concepts of product / technology / process

informational integration for process modeling and process planning

INTRODUCTION

Product creation time has dramatically decreased mainly due to product versatility and diversity. The main reason is an increasing demand of consumer to use customized products. Consequently, product realization is shortening and companies need new software tools and environments in order to be able to collaborate with various partners that are very often different from one project to an other. Product, technology and process modeling is a base for the informational integration during product life-cycle management. But the efficiency of such an approach depends on the possibility of memorization and re-use of knowledge related to product and realization technologies and processes (from the concepts to the physical industrial objects and environments). The base of knowledge is of course technological based but is also related to management and organizational aspects. Information and knowledge management is necessary to support such approach. It remains two major difficulties that are the determination of what is the information that has to be memorized and how to represent them in order to provide an efficient re-use. Many of product life-cycle activities are computer-aided, like design, process planning, production scheduling, maintenance, etc… During these stages, the information and knowledge are related to product, its environment (tools, production equipments), its logistics (delivery) and its maintenance (usage history). These activities concern different competences that need many software which use several formats to represent information contents. These contents have to be presented to the users according to their own points of view depending their competences and needs. In the following are presented some fundamental concepts of product modeling, design process modeling, knowledge-based models related to production processes, and more particularly the link between product, technology and production process [START_REF]Contribution à la modélisation des produits et à l'intégration des technologies productrices dans un environnement multi-acteurs[END_REF] [START_REF]Modèles et approches pour la conception et la production intégrées[END_REF]. Then, some elements of organizational aspects are delivered before a more prospective part of this paper concerning a topic of interest for many industrial and service fields, a global information system for the individual tracking of products during their complete life-cycle.

PRODUCT MODELS

The first initiatives and results in the field of information model related to product have been successful about ten to twelve years ago [START_REF] Krause F.-L | Product modelling[END_REF]. It seems important to underline some fundamentals on functional, structural and geometrical (physical) points of view of mechanical part and assembly modeling.

Functional, Structural, Physical (geometrical) aspects

At the beginning of 90's, C. Mony proposed a product model based on three essential aspects that :

-the functions that correspond to the requirements, -the parts and the components of the product, -the geometry and the physical properties of each of these parts and components [START_REF] Mony | Un modèle d'intégration des fonctions Conception-Production dans l'ingénierie de produit -Définition d'un système mécanique en base de données objet[END_REF]. The feature concept 1 allowed to formalizing both representation, functional and structural properties (accuracy, assembly conditions, etc.). The link with production processes has also been formalized thanks to the feature concept (technological, link, machining, etc.). Some main ideas have also been highlighted related to future orientations for some extensions and applications of these concepts. In particular, « a function can be realized by one or more features or parts », « a part or a feature can contribute to the realization of several functions », « in mechanical engineering, a given model is relevant for a given application », « each point of view needs a particular geometrical model that allows the 1 "a parameterized geometric elements group, handled like an object and having a semantics (a mean) compared to one (or several) function(s) of the product engineering. These groups can be associates various attributes and methods allowing an improvement of the geometrical data and the handling of high level semantics objects" [START_REF] Mony | Un modèle d'intégration des fonctions Conception-Production dans l'ingénierie de produit -Définition d'un système mécanique en base de données objet[END_REF] manipulation of the elements strictly indispensable for the realization of its own objectives », « all the points of view have to be coherent ». Of course, other significant contributions have followed these precursor works. It has to be mentioned the following results obtained during DEKLARE [START_REF] Saucier | Un modèle multi-vues du produit pour le développement et l'utilisation de systèmes d'aide à la conception en ingénierie mécanique[END_REF] [6] and MOKA [7] [8] projects, the chromosomal model based on domain theory [9] or the level-based model (objectives, functions, physical structure, parts and assembly) [10].

Comportemental aspect

A behavioral aspect has been introduced in the product models. This is to say all the elements that characterize every law, data, etc., more generally the performance criteria for the evaluation of the coherency of the solutions relatively to functional requirement. An international well-know initiative, the FBS approach (Function / Behavior / Structure) has supported a new orientation at the beginning of 1990's and has inspired the work of Y. Harani [11]. Equations and variables of behavior have been integrated in a product and process model, joined to a point of view approach. This notion is developed in the following paragraph.

Multi-view aspect

The notion of multi-views has been necessary in order to let the professionals have an access to a unique and integrated product model. This model has to be shared but all the information is not necessary. This is better to have specific semantic and interfaces. On such topic, the work from 3S laboratory has to be highlighted [12] and also those of K. Mawussi who proposed a model integrating the representation of the parts, of the raw parts and forming tools.

Diversity aspect

Diversity is also one of the basic concepts that are necessary to be managed mainly due to the customization demand. A typical example is the one of automotive industry. The theoretical number of combinations is particularly large and is relatively wellmastered. In such approach, automotive companies have proposed some significant initiatives for the proposition of standardized representations of automotive products and means used for their design and manufacturing. One can notice a proposition of important concepts in AP STEP 214 by F. Chambolle, concepts integrated by PSA [15]. The figure 1 represents schematically how the diversity and the structure at different levels (part, solution, assembly, function, vehicle) is taken into account in the model. Based on such a structure, some requests related to any kind of data can be expressed in order to favor the search of information and then the process of decision during the different stages of an automotive project. These models constitute the base for data exchange with co-contractors and can serve as a reference for future projects. They contain both technical and organizational information that represent the links between the automotive product itself and what has to be necessarily used during a vehicle life-cycle.

LINK BETWEEN PRODUCT AND TECHNOLOGY

Product models have to represent efficiently the information needed by the product life-cycle. This implies a better use of CAD environments and also a more efficient capability for the memorization and the transmission of numerical data. But, according to common opinion, a real advantage is depending on the integration of the information related to the product definition with the information characterizing the production technologies and processes.

Technical aspect

This coherent integration has been improved thanks to the results of several works, in particular those of F. Villeneuve [16] then the ones of J. Ben Younès [17]. He has proposed an approach for the integration of both the product (based on features used to describe the shapes of the part, including the properties wanted for the determination of machining capabilities as accessibility, tolerances, etc.), the cutting tools necessary for machining each shape on the part (feature), and strategies characterizing the possibilities of related movement between the tool and the part (sequence). The main result of this work is the TSG concept (Tool-Sequence-Geometry) that allows the specification of the knowledge related to the machining of shapes on a part (Figure 2). This figure presents a partial view of the conceptual model, which shows the links between the TSG concepts and the data necessary for a machining process generation. Thanks to these elements, it is possible to specify knowledge related to a particular skill but this is not

Vehicule Organe Function Solution Part

Category Specification sufficient enough to support the complete loop (from the specification and the choice of the process to the effective realization of the product using the chosen process). A significant contribution for such possibility is the difference concept proposed by S. . This difference is evaluated between a theoretical definition of the perfect technology and the representation of the real physical technology effectively used for the manufacturing of the part. This model, associated to a process planning functionality is able to deliver a first comparative evaluation between the technologies mastered by the company and other emergent ones. This constitutes a factor that can favor the integration of new productive technologies in good conditions. These new productive technologies constitute innovation and competitiveness vectors, in a short and medium term, even more. They constitute a strategic challenge for the company. So, it is fundamental for companies to be able to specify a requirement and to access to capable technical processes in order to obtain a coherent solution in a given technical-economical context. So, the knowledge related to validated solutions, the access to the knowledge of some experts from the company, a realistic perception of actual service capabilities constitute key factors for product development. This is why industrial companies are more and more interested in search engines that allow accessing to some dynamic knowledge from all over the World. This is possible thanks to new active cognitive agents [19] that are software allowing access to data but also giving the opportunity to send requests indispensable to more easily specify particular aspects. These new possibilities constitute a strategic opportunity for product and process integration in order to be able to very efficiently generate process planning for new product according to actualized industrial technologies and services. The cognitive agents are based on knowledge data models that link specification concept to manufacturing process planning. Thus, the most efficient solution today seems to be based on representative validated solutions, corresponding to realistic performance levels actualized depending on the technical capabilities of modeled processes. The goal of such work was to memorize a database with case studies (successes and failures) related to typical rapid product development processes. These processes are mainly applicable to the manufacturing of prototype parts and products but is also concern to industrialization phase. The memorization and exploitation phases are based on an efficient man-machine interface and all the manipulated data are build using the proposed conceptual model. (Figure 3). This model represents the generic fundamental concepts that allow representing case studies and corresponding requirements. This corresponds to different models (user needs, requirement, technology and meta-technology, material, process, service provider company, state (numerical or physical). The user needs definition and the search for a solution are directly accessible via a specialized manmachine interface, based on KADVISER environment. The search engine is basically local for the first step of this approach and works based on case-based reasoning. If no valid solution is found, the system uses the ascendant generation algorithm based on the following principle : "from a final state corresponding to the user requirements, the algorithm selects all the technologies that are able to deliver a part in the final state". Then, for each initial state of each selected technology, the algorithm analyses the initial state of each selected technology. If it corresponds to the initial state given in the user requirements, it memorizes it as a possible solution.

If not, it considers each of these intermediary states as the new final states to be obtained. Then it applies the same principle as longer as the initial state has been found for each branch of process or as longer as there is no technology able to deliver the intermediary state. Such branch is deleted and the solutions are delivered to the user. Each process solution is structured as a succession of states. The transition between two states is characterized by one or several technologies. Such sequence of states and technologies constitutes a process solution. In the future, some efforts are going to be focused on a generalization of this approach for utilization based on cognitive agents connected to a request analyzer. A first experimentation has been to test the approach by the use of distributed databases accessible through Internet. The main difficulties are on one hand the dynamic aspect of knowledge (rapid and frequent changes, new technologies, new performances) and on the other hand the motivation of each expert to contribute to the formalization of his own knowledge according to generic concepts. This second aspect depends on the expert motivation to understand the concepts and to contribute to their evolution in order to improve the efficiency of the use of the memorized knowledge.

Socio-technical aspect

This aspect of complex systems and processes is not so much studied. But, there is an interest in such orientation because industrial environments have to be safe and secured, both for the technical dysfunctional behavior and for user safety. So, it is particularly important to integrate during the design stage some aspects related to the working place and environment and to potential risks due to technical choices for some particular function. This is mainly why the CNRS (National Research Council for Science) has initiated the PROSPER program. In this context, the INRS (National Institute for Research and Safety) and a group of partners the CRAN was in, have decided to propose and develop an initiative based on the taking into account of the working situations during the design phase. More over, one of the goals was to give the user the possibility of evaluating the consequences of particular limit working conditions and their influence on the design of the production systems. R. Hasan [21], in his PhD thesis, proposes an approach based on the working situation concept, and more particularly on the integration during design of socio- technical aspects and the interaction between the technical system and humans during the life-cycle of the production system. The already obtained results and the current display within the framework of a demonstrative software tool let expect possibilities of the approach, becoming widespread within the framework and a generic methodology in order to integrate the life-cycle of the system from the design stage. There are more particular aspects connected to the safety of people during their intervention on the technical system (normal use, degraded modes, change of production, maintenance, After-Sales Service Department, etc.). As the model of the figure 4 shows it, the concept of working situation allows setting up the relations between the technical system and the team of work, whatever the mode of intervention, the task, the tools and necessary consumables in execution of these tasks. One also finds there what can lead in an incident, even in an accident, through the concepts "environment", "dangerous event", "danger zone", "risk", "dangerous phenomenon". The dynamic aspect of the working situations (chain of the operations during tasks and use) appears on this model through the notion of operator of composition but is represented today using Petri's networks. From these last ones, it is in particular possible to obtain and to control the totality of the available procedures in use manuals.

It is clear that numerous research works will be necessary to characterize the most significant and/or influential parameters, with the aim of their evaluation compared in phase of design of the systems. This evaluation can doubtless, considering the current promising initiatives, be supported by tools and environments of the virtual reality favor in which one can immerse operators in their future working frame and put them in virtual contact with the system during the design stage.

This method could be also generalized in any phases of a product elaboration as well as in that of its life when the product is itself a system on whom people should intervene in a sure way during its life (concerning a car for example, during realization phases of the vehicle, during the production phases, during the use phase, during the maintenance operations, etc… of the vehicle itself). It is clear that all the links exist and that the true progress lies in their integration in support on an information system reagent (joinable in the various tools and environments of modeling and simulation) and coherent (based on realistic and evolutionary models taking into account experience feedback at the same time in simulation and during the life of the system).

DESIGN PROCESS MODELS

Elements presented previously are really useful only if the structured information can be managed, distributed, reused. Furthermore, the context of design is directed to a cooperative and distributed frame, because of the shared data and the multi-competence indispensable to the realization of products [START_REF] Salau | La Conception Distribuée : Théorie et Méthodologie[END_REF] [23] [START_REF] Garro | Conception distribuée et émergence[END_REF].

This context bases on basic elements allowing the representation and the memorization of the design process [START_REF] Tollenaere | Conception de produits mécaniques[END_REF]. For some years, numerous initiatives have been concerning this problem of research in purposes of definition and integration of conceptual models of data and treatments, as well as in the definition and in the implementation of informational environments based on memorization of on-going and past project knowledge. It concerns as well elements relative to the product itself as its process of design and elaboration. It became so indispensable to better understand why, how, etc. each of the information is attached to the product. This is why numerous research works aim at memorizing what has to be during the life of the product. One speaks of history, of design intents, etc. [START_REF] Ouazzani | Contrôle de cohérence et gestion de la sémantique dans le cycle de conception-production -Application à la représentation du processus d'élaboration de produit[END_REF].

Formalisms of process representation exist [START_REF] Vernadat | Entreprise modelling and integration: principles and applications[END_REF]. One can quote IDEF3, Petri's networks, GRAI networks, etc.; however, these elements do not constitute a solution in general approach necessary for the representation and for the management of the industrial knowledge. This is why basic elements, richer than those available in the classic approaches were proposed. One can quote for example the works of A. Ouazzani who proposes a model based on the concepts of objective, action, argument and alternative [START_REF] Ouazzani | Process modelling: a design history capture perspective[END_REF]. This structure takes into account the resources to be used (human, physical, software, etc.) as well as the chain of the actions and the structure of the objectives. This model of process is connectable with the model of product through the notion of state. It is managed by specific actions told "management actions".

It is also necessary to mention the propositions of other laboratories in this subject, through the works of A. Saucier and C. Vargas, those of Y. Harani (integrating the notion of task, operator and of release mechanism) and finally those of P. Girard and B. Eynard [START_REF] Eynard | Modélisation du produit et des activités de conception -Contribution à la conduite et à la traçabilité du processus d'ingénierie[END_REF], completing the basic tools of GRAI networks [START_REF] Doumeingts | GIM/GRAI integrated methodology for product development, Design for X, Concurrent engineering imperatives[END_REF] in the specific frame of design. The characterization and the modeling of the processes stay problems on which the researchers keep on working, by trying in particular to widen the application field of the model in all the phases of the product life cycle [START_REF] Brissaud | Product models for lifecycle[END_REF].

ORGANISATIONAL ASPECTS FOR INFORMATION ACCESS

Because of the industrial globalization, the knowledge and the resources are more and more distributed in numerous sites. The necessary implication of the various competences as soon as possible during the life-cycle of products makes that one needs to reach in a fast way a distributed information, structured by knowledge for each skill, under coordinators' responsibility. These last ones have to master at the same time the technical processes, but also the process of development in design. This new mode of organization, e-design, e-engineering, emanufacturing [19] is set up mainly thanks to two catalyst factors that are the "net", the NTIC (New Technologies of Information and Communication) and the formalization of knowledge at the level of specific agents being organized in multi-agents network. These agents are based on models of product, technology, technical and design process such as described previously.

This organization in several levels opens possibilities for the integration of every new agent, but also represents all the difficulty of information search and expertise coordination with regard to a given technical, economic, social, etc. request. Even, numerous research pieces remain to investigate in this domain in strong expansion, the knowledge becoming more and more quickly obsolete.

It is also important to underline critical aspects for the communication intra and extra company. It is related in particular on the quality and the security of the information exchanges , of the traçability of the decisions, or the group dynamic communication during meetings, of works in project structures. It is related to an important part of researches for the scientific community and corresponds to a sensitive aspect of efficiency and the ability to react of companies.

PROCESS: KEY CONCEPT FOR PERFORMANCE

In the whole industrial context, the key factor is the profit, by a use of means economically realistic and by respecting the constraints of inconstancy due to the market. For that purpose, the knowledge of the costs and more generally the value transfers becomes essential during the phases of development then valuation of products.

So, it becomes necessary to be able as soon as possible to measure in different terms (technical, economic, social, of service, etc.), the consequences of a decision on the product (creation, evolution, standardization, diversification, etc.). Consequently, it becomes possible to structure all the processes inherent to the product life from elementary fundamental processes mastered in quality terms, cost and of time.

This approach also constitutes a base of evaluation for the company at the strategic, tactical and operational levels for the choice of fundamental orientations. Indeed, it is then possible to estimate a priori the consequences of such a choice, the opportunity of such other one by the measure of the impact of these decisions on the processes deployed for some product valorisation.

As it was shown first, it is already difficult to memorize enough technical knowledge to be able to suggest optimal industrial processes. This is on these bases that an approach of management by the industrial values becomes possible, by estimating the knowledge and the competence indispensable to deployment of a given process, by mastering the interactions between processes in order to be able to better estimate the consequences of a given modification, etc…

SUMMARY

Through this article, aspects connected to the problem of modelling of products and systems (in link with the processes and the process planning) as well as that of their processes were presented. The content is naturally not exhaustive, but representative of coherent tendencies that open perspectives of these research topics.

It is also question of elements related to the structure of information in link with the current organizations by competence or profession, what pulls information systems always more complexes based on the notion of cognitive agents These systems will be more and more used for the assistance to decision process in all the levels of the company. This can be really realistic industrially only by the mastery of the strategic parameters characteristic of each of the elementary processes of the products life cycle .

The modelling and the assistance to the generation or the evaluation of the processes are one of the key factors products and industrial systems life-cycle mastery. These models and methods are more and more based on the knowledge of different kind, technical, economic, social, environmental, etc… [8]

Figure 1 :

 1 Figure 1 : representation of the basic concepts structuring the model [15]

Figure 2 :

 2 Figure 2 : fundamental structure of TSG concept [17] This last idea has driven the research of A. Deglin [20].The goal of such work was to memorize a database with case studies (successes and failures) related to typical rapid product development processes. These processes are mainly applicable to the manufacturing of prototype parts and products but is also concern to industrialization phase. The memorization and exploitation phases are

Figure 3 :

 3 Figure 3 : data and working situation environment model [20]

  YVARS P.A., Contribution à la représentation des connaissances en ingénierie de produits et de systèmes automatisésde production, Habilitation à Diriger des Recherches de l'INP Grenoble, spécialité Génie Industriel, janvier 2001 [9] ANDREASEN M. M., The theory of domains, Workshop on understanding function and function to form evolution, Cambridge University, 1991 [10] GRABOWSKY H., LOSSACK R. S., WEIS C., Supporting the design process by an integrated knowledgebased design system, Advances in formal design methods for CAD, IFIP International Conference, Mexico, 1995 [11] HARANI Y., Une approche multi-modèles pour la capitalisation des connaissances dans le domaine de la conception, Thèse de Doctorat de l'INPG, 1997 [12] TICHKIEWITCH S., Specifications on integrated design methodology using a multiview product model, Engineering system design and analysis conference, ASME '96, Montpellier, 1996. Thèse de Doctorat, ENS de Cachan, 20 janvier 1995 [14] MILLION O., De l'intégration des métiers par les données techniques vers la maîtrise de la modélisation conceptuelle : la méthode V.I.M. (View points Information Modelling) », Thèse de Doctorat de l'Université Henri Poincaré Nancy I, spécialité Production Automatisée, 21 Décembre 1998, Nancy [15] CHAMBOLLE F., Un modèle de produit piloté par les processus d'élaboration -Application au secteur automobile dans l'environnement STEP, Thèse de Doctorat, École Centrale Paris, 29 avril 1999 [16] VILLENEUVE F., Génération ascendante d'un processus d'usinage. Proposition d'une formalisation de l'expertise. Application aux entités alésage, Thèse de Doctorat de l'Ecole Centrale de Paris, février 1990 [17] BEN YOUNES J., Modélisation des ressources en fabrication mécanique. Application au choix des outils coupants dans un environnement orienté objet, Thèse de Doctorat, École Centrale Paris, 19 janvier 1994 [18] MAGNET-CANET S., BERNARD A., BOCQUET J.C., Un modèle d'intégration simultanée d'une technologie productrice : application à l'UTGV, 4 ème Colloque PRIMECA sur la Conception Mécanique Intégrée, La Plagne, avril 1995, pp 149-155 [19] BERNARD A., BRISSAUD D., Improvement of design efficiency by using fabricability criteria through edesign cognitive agents, CIRP Design Seminar,

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rd International


Alain Bernard

Jean-Charles Delplace

Nicolas Perry

Serge Gabriel

Integration of CAD and rapid manufacturing for sand casting optimisation

Keywords: CAD, Sand casting, Simulation, Rapid prototyping, Rapid tooling

In order to reduce the time and the costs of the products development in the sand casting process, the SMC Colombier Fontaine company has carried out a study based on a tooling manufacturing with a new rapid prototyping process. This evolution allowed the adequacy of the geometry used for the simulation to the tooling employed physically in the production. This allowed a reduction of the wall thickness to 4mm and retains manufacturing process reliable.

Introduction

SMC COLOMBIER FONTAINE is a company of the AFE METAL group, which uses a sand casting process to manufacture steel primary parts. To reduce the « time to market », the primary part producers also need to reduce the industrialisation time and costs. These obligations and the intention of improving the process performances brought SMC to develop the numerical technologies to manufacture the tooling. In order to validate the parts design, the company uses layer manufacturing technologies to make geometrical prototypes.

After it has been validated, it can serve to get functional prototypes with a lost pattern process. Both are used to allow the entire group involved in the project to validate the solutions, by the application of the concurrent engineering concepts for rapid product development [Bernard, 1999 ;Bernard et al., 2000 ;Xue, 1996]. These improvements are nowadays inked into the company culture. The next steps for the industrialisation time and costs reduction is the introduction of the rapid tooling technologies. For the sand casting, the processes are the Stereolithography, the Powder melting (EOS-DTM), the layer cutting out (LOM), the layer machining (Stratoconception), and the 3D machining, which is the most used [Barlier, 1998].

But to be able to generalise these kinds of technologies, the CAD study is an inescapable step in the part industrialisation. The whole improvements led by the numerical technologies should justify the investment in time spent to do CAD modelling of all the different elements in the sand casting process. But, like most companies that manage a large product mix, SMC uses at the moment CAD only for part design.

The content of this paper is to demonstrate the efficiency of the proposed approach which objective is to generalise a complete numerical reference by introducing CAD, simulation and new manufacturing technologies in order to be able to optimise the product and its process.

Industrial context of the project

SMC is characterised by a strong product mix with 7 different business lines, about 1000 revolving references per year and an average of 15 new tooling per month. Furthermore, the sand casting process needs, at the moment from 20 to 40 hours to complete a CAD study; that is to say, model the part, the master pattern, the pattern-plates, the cluster and simulate the fill up and the solidification. To generalise this kind of study to all the parts is not possible at the moment compared to the technical office capacities. Therefore, the toolmaker suppliers use the traditional moulding techniques to manufacture the pattern plates from the 2D drawing or from the part CAD model. The random repeatability of the tooling penalises the simulation accuracy. Therefore, there are only some clusters that are simulated and the results are interpreted with cautiousness. The numerical tooling should lead to improvements from the manufacture accuracy. Indeed, at the moment, the traditional moulding technique accuracy is about 1 millimetre when the rapid tooling technologies are closer to a tenth. It allows the parts tolerances improvement, the machining allowances and the flash reduction. It also gets more reliable simulation results by the adequacy between the CAD model and the real cluster geometry. It optimises the overall product industrialisation time and costs by the reduction of the iterations needed to perfecting the serial production design. Furthermore, the improvements in the metallurgical quality allow the reduction of the wall thickness while bringing down the misrun or the breaking risks. Therefore, the casting parts become a technological alternative less and less risky compared to the welded or the machined parts.

Content of the study

To be able to validate these concepts, SMC made the following study. The part chosen for the trial is manufactured, at the moment, by a welding process. To modify the process, the most important criteria are price, weight, mechanical properties and metallurgical qualities. To respect the price and the weight requirements, SMC was obliged to reduce the wall thickness under the limits of the process, that is to say 4 mm for a minimum of 6 mm. The study started with the part design and their assembling to create the cluster (Figure 1).

Risk area after modification

The pattern plates and the core boxes were designed with the cluster modelling. brings into play materials exploitable in paste form, which allows a large application range. Indeed, the resin paste permits a high level of additional material, which increases the mechanical properties. The paste is set down into thin layers with specific scrapers, then, solidified by a laser. This process also uses a ceramic paste to obtain parts or cores [Doreau, 2001]. At present, the interest of such technology has been validated on a technical point of view concerning the manufacturing of ceramic components and tools but also for alumna and metallic parts. Unfortunately, it is not definitively assumed that layered-manufacturing techniques is economically comparable with machining for the manufacturing of the core-boxes. Afterwards, the pattern was inserted into the standard pattern plate. 20 hours of work were needed for the assembly. The manufacture and the assembly time can be optimised easily. Indeed, the marketed machine capacities are now of 500x500x500mm at the maximum, which means that the pattern should be manufactured in one time. Furthermore, the holes necessary to assemble the centring lugs and the whistler-spiracle should be inserted into the numerical model to avoid the drilling. The tooling has finally received a surface treatment to improving the abrasion resistance. (figure 5).

Figure 5 Tooling assembly and pattern plate

Technical results 500 moulds were produced and the results were very good. The core box and the pattern plate did not show any defects. SMC uses a fully automatic molding site that uses natural set sand (without resin polymerization). It is plastered against the pattern plate by an explosion and then some piston squeeze the sand mould with a pressure of 12 Kg/cm 2 or 84 bar. Therefore, the molding process used in SMC is very aggressive in terms of abrasion and compression resistance. This operation takes place in the ambient temperature and the tools do not warm up a lot. So, with a maximum of 40°C, the temperature resistance is not as important for example as it is for the plastic injection. The pattern-plate was surface treated and, in the most exposed areas, the protection coat disappeared but the rough material has not suffered from the abrasion (Figure 6).

Figure 6 Test closing mould

The OPTOFORM process was validated, without any problems, with this small production. Unfortunately, we did not have the opportunity to test it for a bigger production, but the tools state at the end of the trial, looked like the production ones. Therefore, the estimations about the tooling production capacity are about several thousands of moulds (figure 7).

Time and cost progresses

The following figures show the average time of all the operations that composed the industrialisation with and without the numerical channel. The improvement in term of time is about 20%. Unfortunately, this trial has shown the difficulty to justify the development costs payback. The following figure shows the overall development costs for the trial (figure 8).

Figure 8 Product development time and cost

The overall development costs were about 15% more with the numerical channel when with the traditional techniques. This difference was due to the difficulty to realise the complex moulding study with the CAD tools; that is to say, model the complex split joints, manage the moulding looses, etc. At the moment, the toolmaker has progressed to improve this skill while the casting designer has lost it. Indeed, when the CAD was introduced in the foundry, the choice was restricted to the professional systems used by the customers (CATIA, Pro-engineer, etc.). Actually, the foundry design offices are composed of casting engineer without CAD skill. The training and the integration of this kind of tools are difficult. Furthermore, the hourly rate is expensive, the time spent is important and the design costs rocket. These are the reasons why the payback was not possible. Therefore, the way to generalise the CAD study is to pass by the userfriendly improvements and the specifics tools developments. SMC started this mutation during 2000 by the introduction of user-friendly CAD software. The main three are Think3, SolidEdge and SolidWorks, which are all modern software, easy to use and to setup on a usual PC. The choice was SolidWorks, which has the best userfriendliness and the most compatibility with the window products. It introduces a new outlook on the CAD. It stops thinking of it as a professional tool and thinks of it as an office automation application. The CAD software becomes a usual icon in the office-shortcut bar like Word, Excel or PowerPoint. Furthermore, the foundry designers are casting and not CAD professional. So, they need tools to help them to design to parts with the easier and the quicker way to do it. Furthermore, SolidWorks was installed on laptops, which gives the relevant flexibility to train and use the software. It also leads improvements in the ways to communicate with the customer. The concurrent engineering becomes as easy as to go to the customer and to work with him straightaway on the CAD project with the laptop. It also simplifies the way to send the files by e-mail for example to a prototype supplier or to a representative. These improvements are common nowadays but they took much more time with the CAD systems that were installed on workstations. The flexibility introduced by the couple SolidWorks-laptops leads to a massive reduction of the CAD hourly rate due to the system price and to the time spend on it. The next figure shows the cost results for the complex parts in 2001 (Figure 9) It highlights the reduction of the design costs thanks to a difference about 20% cheaper with the numerical channel when with the traditional techniques. These results can be more improved by the development of specific design tools. They should manage the quicker way to complete moulding study from part design. In this way, the numerical chain has been generalised for the complex parts as well.

Conclusions

By the achievement of this study, SMC introduces a rapid prototyping technology able to manufacture the production tooling for the sand casting process. The 500 moulds manufactured prove the feasibility for a small production and the good tooling statement allows expecting the same results for the medium production (several thousands). It also proves the improvement in the simulation reliability thanks to the good metallurgical results, in spite of wall thickness reduction under the process limits. Next to the technical validation, the payback analyses highlight the problem of cost lead by the achievement of the entire CAD moulding study. The successful introduction of SolidWorks reduces part design time and CAD hourly rate. In order to reduce the design costs sufficiently to generalise the numerical chain, SMC decided a specific development of particular design tools completely dedicated to the design of raw parts and tools. The development has been achieved at the end of 2002 [Bernard et al, 2002a ;Bernard et al, 2002b] and, since this date, all the new products have been designed and industrialised using the numerical chain and the design methodology [Bernard et al, 2003]. All these improvements have shown SMC an interesting way of progress to bring the sand casting offer to be more competitive.

Figure 1

 1 Figure 1 Cluster CAD model

Figure 2

 2 Figure 2 Filling up and solidification simulations

  A new rapid tooling process manufactured the master-patterns. This technology was introduced in 1998 by OPTOFORM (Schaeffer and al., 1998], which was purchased in 2001 by 3D Systems [3D Systems, 2001]. This validation for the sand casting process played a part in the industrial development

Figure 3

 3 Figure 3 OPTOFORM process diagram

Figure 4

 4 Figure 4 Pattern and core boxes rough prints

Figure

  Figure 7 Final part

Figure 9

 9 Figure 9 New product development costs

Figure 10

 10 Figure 10 Cost corresponding to sample parts