Sergej Bondar
email: sergej.bondar@opendesc.com

Leo Potjewijd
email: leo.potjewijd@skf.com

Josip Stjepandic
email: josip.stjepandic@opendesc.com

Challenges and Solutions in Customer Process Based on Collaborative Engineering

Keywords: Collaborative engineering, distributed development, CAD data exchange, CAD data translation

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

INTRODUCTION

Nowadays modern manufacturing industries like automotive are acting in the dynamic global marketplace that demands instant responses to customer requirements, short time-to-market and high flexibility in production. In the past decades the manufacturing industries were even more shifting to a distributed environment like an extended enterprise with increasing agility. We set the customer's satisfaction on the first place in order to get the assignment against many competitors. This has caused the mass customization at high level and even more complex development, manufacturing as well as logistics processes along the manufacturing supply chain. Thus the upcoming outsourcing has derived a multi-tier supply network structure involving numerous enterprises around the globe. The product development as well takes place in global development partnerships. OEMs accomplish the development of new products at many locations in several countries across the world [START_REF] Stark | Global Product. Strategy, Product Lifecycle Management and the Billion Customer Question[END_REF]. Furthermore a variable number of external service providers and suppliers take part in individual projects. The most relationships in this supply network are temporary, exceed by the end of project and today's project partner can quite become tomorrow's harshest competitor (Fig. 1). The suppliers were involved in the product development processes as early as possible, because they mostly possess a greater depth of domain expertise, which is necessary for best product development. The OEM-supplier relationship is characterized by a sequential interaction whereby the OEM gives clear product and production requirements to the supplier and the supplier delivers the product or service to the OEM. Supplier integration is a crucial method for incorporating a supplier's innovativeness in the product development process and reduce the costs and risk [START_REF] Dyer | Collaborative advantage: winning through extended enterprise supplier networks[END_REF]. It also creates synergy through mutually interacting deliverables and decisions between OEM and suppliers. Both sides take advantage of each other's capability to develop the product as well as to obtain feedback from the other party to improve the product development. Due to the complex development cycle, the OEM took the lead and has begun to adopt supplier integration into its product development process. To respond to this trend, the collaboration and partnership management between the OEM and suppliers need to be continuously improved to reduce costs and time. Regarding the depth of collaboration, the integration of suppliers into the OEM process chain can be defined in many ways, depending on corresponding work package and type of collaboration [START_REF] Tang | Collaborative Supplier Integration for Product Design and Development[END_REF]. To enable the success of supplier integration, this work describes how to shape the collaboration between the OEM and its suppliers, through determining an appropriate supplier integration method and using the proper tools. In the context of concurrent and collaborative engineering, the validity and consistency of product information become important. However, it is difficult for the current computer-aided systems to check the information validity and consistency because the engineers' intent is not fully represented in a consistent product model. Due to the different approaches and IT systems in the automotive OEM industry, a unified solution is not possible at this time. In particular, automotive suppliers that develop system components for a number of different OEMs or tier-1 suppliers, face the chal-lenge of ensuring that they make the CAD data available in the format required by their customers and with a high level of reliability and, if data translation is involved, that they take the system configuration of the respective customer into consideration. Special requirements like the flexibility for further changes in business relationships and the intellectual property protection are also taken into account.

COOPERATION MODELS

As the outsourcing became standard business approach in the manufacturing industries, many industry associations like the German automotive manufacturers association (VDA) accomplished the basic development work to define and classify the typical collaboration models and corresponding processes [START_REF] Vda | VDA Empfehlung 4961/3, Abstimmung der Datenlogistik in SE-Projekten[END_REF] (Figure 2). There are 6 supplier types defined according to the criteria: production technical integration, process integration, functional integration, and geometrical (spatial) integration of the whole product (car). Beside of the prime contractor who can be defined as a clone of the OEM without the product management, sales and marketing function, all other types of suppliers (system supplier, module supplier, component supplier, part supplier, and engineering service provider) maintain a high level of independency in their corresponding processes. Taking the fact into account that a supplier supplies many customers, who have their own, various processes and infrastructures, there yields a strong need for a comprehensive integration approach based primarily on standards and serving the relationships to all the customers. The responsibility of suppliers to provide the suitable product documentation in each phase of product emerging process is self-evident for an OEM. Thus the supplier is forced to take the corresponding measures to adapt his data to OEM's requirements.

CASE SKF

The SKF Group is one of the leading manufacturers of precision bearings, seals, mechatronic components and lubrication systems. It also offers customers a wide range of services including maintenance services and condition monitoring. Founded in 1907 in Sweden, the company is a global player with 110 manufacturing sites distributed around the world and represented in over 130 countries. In the 2012 business year, the Group, which has over 46,000 employees, generated sales of 64.6 billion Swedish krona or the equivalent of 7.1 billion euros.

Fig. 3. Product platform "Bearing and units" at SKF

SKF is organized into 2 Markets servicing more than 40 customer segments. While the Industrial Market takes care of industrial original equipment manufacturers (OEMs) in the energy, railway vehicle, machine tool, medical, food and beverage and other industries, as well as the respective aftermarkets, the Automotive Market supplies manufacturers of passenger cars, trucks, buses, two-wheeled vehicles, and their authorized service centers, with wheel bearings, tapered roller bearings, small deepgroove ball bearings, seals, special products and spare parts kits (Figure 3). The Automotive Market is subject to enormous time and cost pressures due to global competition. In order to set itself apart from the competition, SKF invests a considerable amount of money in research and development, resulting in numerous innovations. The increasing complexity of the components that need to be embedded in an overall solution means that the amount of coordination required between SKF and its customers naturally also increases. Many SKF's products for the Automotive Market are designed based on customer specifications, which is why developers have to work closely with OEMs and tier-1 suppliers. To ensure the greatest possible proximity to customers, application development is decentralized to a great extent (Figure 4). It involves teams comprising of rarely more than 12 members of staff that are distributed over 14 development sites in ten countries. Cross-site collaboration is facilitated by the fact that SKF uses the CAD software Pro/ENGINEER throughout the corporation and manages the CAD data centrally using the PLM solution Windchill PDMLink. As far as external data communication is concerned, however, this means that data constantly needs to be converted into other formats.

REQUIREMENTS AND WEAKNESS IN THE CUSTOMER PROCESSES

Where data communication is concerned, automotive suppliers have to take numerous requirements into consideration that are not always easy to fulfil. Not only do they have to make their CAD data available in the format of the authoring systems used by their customers, but they also need to maintain their respective system environments (system configuration, version, starting model, etc.), which sometimes vary from one vehicle program to another. They have to log exchange processes so that they can provide proof of who received which version of the data when. The changes in the development process require a high degree of automation to make the increasing number of exchange processes manageable. At the same time, aspects such as intellectual property protection (IPP) must be given due consideration when converting data since it is possible that the project partners in the distributed development network are competitors. Last but not least almost each OEM prefers the use of a rich PDM client of his own PDM system on the supplier site for the data export and import. Such client must be bought and licensed, and presupposes an expensive internet access with high bandwidth. That is the reason why many suppliers employ additional resident engineers on the corresponding OEM's sites who do nothing else but data management.

Even if the engineers at SKF are developing bearings and seals for tier-1 suppliers, they often have to send the CAD data to the automotive OEM in question because the components involved are safety relevant and have to be simulated in the context of the whole vehicle. As a rule, the OEM's own data exchange specifications are used, which means that suppliers have to make the data available in the format used by the OEM's CAD system. As far as SKF was concerned, this meant that the company had to support approximately 20 different CAD configurations with several versions of a single CAD system. Data exchange was not even straightforward with customers who, like SKF, used Pro/ENGINEER The requirements relating to the quality of the data to be exchanged are not uniform throughout the entire development process, something which must be taken into consideration when designing the exchange process. As long as the design is being harmonized and optimized in a dialog with engineers at the OEM or tier-1 supplier, requirements relating to data quality are not excessively high. Subsequent to formal release, however, the procurement managers insist on the data being made available according to the contractually agreed guidelines. These guidelines fill volumes since they include not only the data format to be supplied but also the standards, protocols and methods that must be adhered to for the actual data exchange [START_REF] Fischer | Anwendungsorientierte Optimierung des neutralen CAD-Datenaustausches mit Schwerpunkt Genauigkeit und Toleranz[END_REF]. In many cases a significant manual rework is necessary to supply the data according to those requirements.

A great deal of know-how is embedded in the parametric design models of the bearings as features, formulas and dependencies, and this know-how must not end up in the wrong hands. In the past, the different translation processes meant that a great deal of manual intervention was required to simplify the data during translation and avoid revealing too much intellectual property [START_REF] Liese | Securing Product Know-how by Embedding Intellectual Property Protection into the Organization[END_REF]. The assemblies could not simply be converted into a single part because certain attributes of the individual parts such as, for example, mass or center of gravity, are needed for the calculations and simulations [START_REF] Wendenburg | Kein Datenaustausch ohne Datensicherheit[END_REF]. Certain details do, however, have to be removed as they could reveal how the engineers at SKF solved certain problems from a technical point of view. Thus an additional step became necessary to derive the customer models from the original models.

As is the case with many automotive suppliers, data communication at SKF in the past was characterized by heterogeneous translation and exchange processes, which made traceability more difficult and time-consuming. Translation and data exchange were not integrated, which meant that the files passed through numerous hands. Although the quality of the converted data normally satisfied customer requirements, the costs involved in preparing and transferring the data were relatively high and the data was not always delivered on time. Many weak points were identified.

In addition to Pro/ENGINEER, several business units of SKF Automotive also maintained other CAD systems whose sole purpose was to convert the Pro/ENGINEER data into the respective target format and adapt/rework the converted models and drawings in particular. Maintaining this menagerie of CAD systems alone was costly, without including the time required for user training. And if the specialist for a certain CAD system went on holiday or changed jobs, there was always the danger of not being able to deliver data on time.

Most business units in the Automotive Market had the local engineering service provider, who maintained a close relationship with the respective OEM and was familiar with its CAD requirements, convert the data. However, the collaboration with different partners was not idealneither with regard to cost nor in lead time. Bearings do not involve a large volume of data, which meant that the amount of data to be converted for each partner was not very big. As a result, the translation orders never qualified for the more favorable terms and were never processed the fastest.

Another cost driver was data communication itself due to the fact that different, sometimes country-specific, protocols and OEM-specific exchange processes had to be supported [START_REF] Hering | Beim Datenaustausch macht Masse die Klasse[END_REF]. SKF normally uses the OFTP protocol in conjunction with ENX, but several customers ask for ENGDAT, which required additional software and support capacity from the outsourced IT department [START_REF] Barkholz | Trans-Atlantic networks link up to ease automotive data sharing[END_REF]. In addition, customer requirements sometimes change from one project to the next [START_REF] Wendenburg | Ein System für alle Datenaustauschfälle[END_REF]. In view of the large number of parallel projects, it was becoming increasingly difficult to organize the data exchange processes in line with current requirements (Figure 5).

SOLUTION APPROACH

Since the data communication is not one of the core competences of an automotive supplier, there the question arises as to whether the companies want to take this task into their own hands or whether they should outsource it to an external service provider [START_REF] Sendler | Komplexität ist die größte Herausforderung[END_REF]. The answer depends on the number of exchange partners involved, the variety of the exchange scenarios to be supported, the data exchange frequency and volume of data to be exchanged [START_REF] Wendenburg | Konvertierung als Dienstleistung[END_REF]. In the case of SKF Automotive, outsourcing data translation and exchange promised a return on investment of less than three years. The bearing manufacturer reached an agreement on a cost model that comprises a flat rate for maintaining the services and a rate for the converted and exchanged data volume. This typical pay-per-use scenario makes the costs predicable and accountable for each development project.

To make data communication more efficient, SKF Automotive chooses a uniform solution for all the application areas and sites. A key requirement of the solution and one of the primary reasons for selecting the dedicated service provider was the provision of both data translation services and the organization of data exchange processes with SKF's customers (OEM and tier-1 suppliers) (Figure 6). SKF selected a central service provider for the customer process so that it could avoid having to develop competences of its own if possible. The web-based OpenDESC.com portal offered the added advantage that it required almost no infrastructure nor initial implementation effort and could therefore be rolled out at the various SKF sites very quickly. The basic prerequisites for use of OpenDESC.com are the web browser and fast internet access.

As technological base the OpenDXM software is used which allows workflow automation of typical data management activities in engineering like import, export, convert, check, send, receive by embedding the corresponding software tools (CAD, PDM, check tools, EDI.). The communication logic of SKF including all communication partners and corresponding persons is stored in the OpenDXM database and controls the data exchange processes preserving a high level of traceability. The software is installed at PROSTEP site including all communication components and devices (ENX, EDI). The access by the end-users at SKF site is given with a web-interface. Fig. 6. Data exchange CAD via www.OpenDESC.com Following a short period of preparation, SKF Automotive started using the central translation and data exchange service at the beginning of 2008. Mapping the exchange partners with their customer-specific requirements regarding translation, quality assurance and data availability took just a few weeks since the data exchange specialists at PROSTEP were able to take advantage of a large pool of existing profiles. Data communication functioned straightaway, with just one exception. There was initially a slight coordination problem with one OEM, which the PROSTEP specialists were able to solve quickly and to the users' complete satisfaction. Since then, the solution has been running smoothly.

To quickly bring users up to a uniform level of learning, key users were named throughout the company. These users were given half a day's training in how to use the solution, and today they are the people which the broad mass of users contact, if they have problems. In addition, PROSTEP offers webinars that allow users to improve their knowledge of the solution and reduce the number of operating errors. In principle, any user at the company today can initiate an exchange process. All they have to do is log on to www.OpenDESC.com, upload the data and select the exchange partnerall the other processes are executed automatically in the background, or if problems occur, they are solved by the translation specialists at PROSTEP within the framework of the agreed terms of delivery [START_REF] Reim | CAD-Konvertierung: Motivation, Probleme, Lösungen[END_REF] (Figure 7). Despite of high progress of the information technology there are still task which must be done manually (repair of grave data quality problems, accurate comparison of drawings). Users at SKF have readily accepted the solution because the amount of time and effort required for data communication has been noticeably reduced. Today, the portal solution is being used at all relevant development sites. A total of more than 100 exchange relationships with the corresponding translation requirements are currently being stored, not all of which, however, are always active. The solution is currently being used for communication with almost 50 OEMs and five tier-1 suppliers at almost 90 locations (Figure 8).

The relatively low number of suppliers can be explained by the fact that SKF uses the normal supplier portal to exchange data with smaller manufacturing partners since the data exchange requirements involved are not as high. The suppliers often also receive drawing data. Last year, SKF converted approximately 4 GB of data via the PROSTEP portal, which was a greater increase than originally planned.

With the reduction of the number of tools for Data Exchange in SKF the company has achieved an ROI of 2 years. This is excluding the increased efficiency by using dedicated trained resources. Therefore the outsourcing is a success for SKF (Figure 8).

The most important benefit of the solution is knowing, that customers will receive the desired data at the agreed point in time and with the stipulated level of quality. Compliance with delivery dates has improved perceptively, which means that customers can be promised delivery on a certain date with a clear conscience. The company expects to reap additional benefits from linking the portal solution to the PLM system Windchill, which will allow data exchange to be better integrated in the customer's engineering change processes.

CONCLUSIONS AND OUTLOOK

In a dynamic collaborative environment like global automotive industry the working conditions are undertaken continuous change. Suppliers who work together with different OEMs and tier-1 suppliers have to constantly cope with new requirements relating to exchange partners, data formats, system environments to be supported, quality and security requirements, etc. If they take data communication with their customers into their own hands, this means that they have to constantly adapt their data translation and exchange processes to the ever-changing requirements. This involves considerable administrative overhead in terms of time and money, which can on occasion have a negative impact on quality and adherence to deadlines. Collaboration with a competent service provider is therefore an interesting alternative as it not only cuts costs but also facilitates making the exchange processes uniform and ensures a higher level of reliability and traceability. Good example for the long-term stability of SKF's approach is the recent move of Daimler by replacing CATIA with NX. While the other suppliers which provide the data communication by their own are forced to adapt their infrastructure, processes and methods to new environment at Daimler by spending a significant amount of money and time, SKF has no need for action because this scenario is included in their service contract with OpenDESC.com.

Whether outsourcing is worthwhile depends on various factors such as the number of exchange partners involved, the volume of data, requirements regarding data quality, etc. The example provided by SKF, however, makes it clear that the ROI for such an investment can be calculated relatively well.

The future development belongs the further automation of whole communication process and provision of "communication plugin" [START_REF] Mervyn | A 'Plug-and-Play' Computing Environment for an Extended Enterprise[END_REF] for each OEM based on recent standards (STEP AP242 and JT) to avoid the expensive point-to-point connection.

Fig. 1 .

 1 Fig. 1. Virtual enterprise in automotive industry.

Fig. 2 .

 2 Fig. 2. Virtual enterprise in automotive industry.

Fig. 4 .

 4 Fig. 4. SKF design centers worldwide

Fig. 5 .

 5 Fig. 5. Data flow required for Global data exchange

Fig. 7 .

 7 Fig. 7. CAD translation via www.OpenDESC.com

Fig. 8 .

 8 Fig. 8. Data flow when using www.OpenDESC.com


Klaus Müller

Klaus Müller-Lohmeier

Additive Manufacturing as Integral Part of the Digital Solution Process -An Industrial Short Note

Keywords: Digital process chain, rapid prototyping, additive manufacturing, design-driven manufacturing, serial production, plastic laser sintering, longterm behaviour, cyclic loading

de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

INTRODUCTION

Festo is a leading world-wide supplier of automation technology, figure 1. As a globally-oriented and independent family company with its head office in Esslingen, Germany, it has become the performance leader in its industry over the last 50 years, thanks to its innovations and problem-solving competence in all aspects of pneumatics as well as its unique range of industrial training and education programs. Today, the company provides pneumatic and electric drive technology for over 300,000 customers in 200 industries world-wide both for factory and process automation as well as cutting-edge training solutions.The Festo group achieved sales revenues € 2,24 billion in its fiscal year 2012 and with 16,200 employees is represented world-wide in 250 locations.

PARADIGM SHIFT IN DESIGN

Another big benefit of applying additive techniques is the possibility to liberate design from manufacturing. The layer-wise and tool-less build-up of parts allows for example now internal structures and bending channels (to put it in other terms conventionally you will not be able to drill around 2 corners !) as well as a function integration (eg. direct co-build of hinges) and a reduction of parts and assembly efforts, figure 4. Now manufacturing follows design leading to complete new design solutions! A highlight of this aspect is certainly the so-called bionic handling assistant. Flexible movement and precise gripping: at first glance, the bionic handling assistant appears to be a resilient gripper arm whose structure and overall functional principle imitate an elephant's trunk. However, above and beyond its actual benefits, the bionic handling assistant is a development platform combining a wide range of technologies and components -from manufacturing concepts to series products like sensors and valves, actuators and grippers, to control technology and software for developing applications and products. This platform, as other solutions of the bionic learning network of festo, shows future concepts for tomorrow's industry and new perspectives in hazard-free human-machine cooperation. The bionic handling assistant is thus an example of how structural flexibility can be realized and adaptive soft-gripping features can be included by using additive manufacturing technology. All parts are made by plastic laser sintering leading to this unique design.

Fig. 1 .

 1 Fig. 1. -Think global, act local: Festo at a glance

Fig. 2 .

 2 Fig. 2. -Additive Manufacturing at Festo

Fig. 3 .

 3 Fig. 3. -Additive Manufacturing is a part of the digital solution process !

Fig. 4 .

 4 Fig. 4. -Additive Manufacturing is more than just another manufacturing technology !


Nikolai Zaepernick

From Rapid Prototyping to eManufacturing

Keywords: Digital process chain, rapid prototyping, additive manufacturing, design-driven manufacturing, serial production, plastic Laser Sintering, handling & robotics, medical implants 1

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

INTRODUCTION

EOS was founded in 1989 and is today the world-leading manufacturer of Laser Sintering systems.

Laser Sintering is the key technology for e-Manufacturing, the fast, flexible and cost-effective production of products, patterns and tools. The technology manufactures parts for every phase of the product life cycle, directly from electronic data. Laser Sintering accelerates product development and optimizes production processes.

EOS serves customers in more than 50 countries operating sales, application and service offices in 11 countries. With its focus on innovation, EOS reinvests a large portion of its revenues into R&D, resulting in a strong patent portfolio with more than 700 active patents in nearly 100 patent families.

EOS completed its business year 2012/2013 with revenues of more than 110 million with a worldwide staff of almost 500 employees, thereof 320 in Germany.

THE HISTORY OF HIGH SPEED CUTTING

High speed cutting today is probably the most exciting example for a production technology in terms of productivity. However this has not always been the case. It took quite a while for milling to get where it is today. It all began in 1818 when Eli Whitney (USA) designed and built the first milling machine for metals. Industrialization has then generated a huge pull for machines toolsmanual and semi-automated machines were about to rise. In 1952 J. Parsons constructed the first NC machine using punch tape for machine operation. From the 1970s onwards, CNC machines developed. Today the High Speed Cutting technology (HSC) is available providing cutting speed over 5.000 m/min, feed rates factor 10 higher than normal milling and thus 30% higher material removal rates. Even surface quality is superior at much higher productivity levels. The core question is: 'Why did it take so long for HSC to be established in production'?

Interestingly Dr. Salomon was granted the first HSC patent in 1931 and Lockheed proved HSC feasibility in the 1950s at 10 times the speed (material removal rates >200 than actual machines at that time).

It's about 'Crossing the Chasm' as Geoffrey A. Moore describes in his famous book. The technology had to surpass a critical mass before being widely accepted in the market.

Two catalysts were necessary for this development:

 Strong customer pull: Aerospace companies experienced plane ribs to require enormous chipping effort, more than 90% of total cost related to the part production were related to milling.  Technology push: New carbide metal tool materials and motor spindles were developed

READINESS OF ADDITIVE MANUFACTURING TECHNOLOGIES

Additive Manufacturing technologies provide high value compared to traditional manufacturing methods. The freedom of design almost makes traditional design obsolete. Engineers can freely design their parts almost without restriction of the production process. Industry experts talk about a 'design-driven manufacturing' process instead. This freedom of design allow for lightweight design as well as very complex geometries. Furthermore, integrated functionality help to save assembly effort after manufacturing and integrate this production step in the Laser Sintering process itself. This way, hinges and other functional elements can be 'printed in one shot'.

Additive Manufacturing machines make economies of scale obsolete. An economic production of 'lot size one' is no issue any longer. The machine does not care to produce 100 completely different parts or 100 similar parts at the same time. This is the start of mass customization.

Finally, Additive Manufacturing has its roots in the Rapid Prototyping field. A major value proposition is the fact, that machines can produce parts overnight. Time to market has a major influence on R&D processes and thus open up doors for much more flexible and short term focused product developments.

Fig. 3. -Key differentiation criteria for Laser Sintering

Are Additive Manufacturing methods yet ready to replace existing production methods like casting or injection molding on the plastic side? At this point in time certainly notthere are some hurdles to be overcome for the broad field of all applications.

Firstly part quality is key and needs to fully comply with customer requirements. This comprises mechanical properties as well as dimensional accuracy and surface quality. With this as prerequisite, AM processes need to be robustwithin the build platform, between several jobs, machines and even suppliers. Finally different industries require specific certifications or quality assurance methods and thus also need to be respected.

In many cases, Additive Manufacturing already fulfills these requirements. There are already very interesting applications out there where Additive Manufacturing is a fully accepted mass production method.

And looking ahead on the product roadmaps of AM machine OEMs, the major imitating factors like productivity or build size are being addressed in the near future.

APPLICATION EXAMPLES

For example dental copings and bridges are a 'lot size one' application. Today, there are multiple machines installed to produce 4-5 million individualized metal bridges and copings per year. The same applies to drill guides for orthopedic surgery. These plastic parts are produced in the ten thousands area per month fully leveraging the possibilities of Laser Sintering.

Another very promising application lies in the area of handling & robotics. Lightweight and integrated functionality are the key features making the difference to existing manufacturing methods.

Fig. 1 .

 1 Fig. 1. -EOS installed machine base 2012

Fig. 2 .

 2 Fig. 2. -Schematic development of High Speed Cutting

Fig. 4 .

 4 Fig. 4. -Implementation hurdles for Additive Manufacturing

Fig. 5 .

 5 Fig. 5. -Example lightweight gripper developed by Kuhn-Stoff


M Schichtel
email: markus.schichtel@bmw.de

Knowledge Retrieval in Complex Information Landscapes Related to Products and Production

Keywords: Information Landscapes, Semantic Search, Knowledge, PLM, Manufacturing 1

scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

INTRODUCTION

Developing and manufacturing complex products such as vehicles today creates an increasing amount of information and knowledge that is by far not stored in a single data source like a PLM-system. Over time the number of isolated information islands has grown to a point where nobody oversees anymore how particular pieces of information are linked together that actually form a complex information landscape. In [START_REF] Siemens | Herstelleralbtraum: Ein Produkt mit Funktionsfehlern[END_REF] a good example is given explaining what consequences could arise, if a specific dependency e.g. between a safety sensor and an environmental side condition remains hidden in a complex information landscape describing the functions of a car. That article points out in particular that the missing information that could have resolved the problem before product launch was simply located at an altogether different location.

To put this observation into another context it shall be pointed out (see fig. 1) that nobody can possibly know all available data sources in a large enterprise. Rather each of the people involved either has the needed piece of information in his memory or searches for it in those data sources that are personally known. Looking at the pie chart reveals that this way approximately only 10% of information and knowledge is tapped into. By far the largest portion is knowledge (approx. 90%), that an individual is not even aware of that it exists ("I don't even know that I don't know"). In fact making it possible for the individual to "sail this (to him) unknown sea of knowledge" is a major challenge today. An interesting and strong corroboration of this observation is the following quotation from [START_REF] Taleb | Der Schwarze Schwan[END_REF]: "Gelesene Bücher sind längst nicht so wertvoll wie ungelesene. Eine Bibliothek sollte so viel von dem enthalten, was man nicht weiß, wie der Besitzer angesichts seiner finanziellen Mittel … hineinstellen kann" 1The challenge of dealing with isolated information islands (or information silos) has drawn top management attention as pointed out in [START_REF] Bongard | Interview with Randy Mott[END_REF]:

"… in order to answer a question information silos are a hindrance. … How many different locations do I have to visit in order to put many single pieces together for meaningful information? Information must be accessible to all decision makers throughout the enterprise."

Figure 1 can also be interpreted as the vast offer of knowledge in any enterprise that is waiting to be uncovered again by the user that has a great potential of matching the pressing demand for information and knowledge from prior experiences. The following short list shall illustrate this demand showing a great bandwidth of complexity:

 What does "CFK" stand for?  Who is the right contact to discuss an issue with the fender?  What module does part "4711" belong to?  What would be an alternative material for this alloy?  What issues did we have with the headlight in former car projects?  What would be the environmental impact of using this coolant instead of the one in use today?

But digital information alone is not the whole story. Lots of information and knowledge is also buried in hardware prototypes! In former times the classical way of validating a product was putting hardware prototypes together. The process of putting together gave rise to insights into problems right away and naturally gave answers to questions not explicitly asked before, i.e. the physical prototype answered the question of "Does it work?" implicitly as a whole. The people carrying out the validation process gained a tremendous treasure of knowledge of experience with no particular need to store this knowledge digitally in data sources. However today, with the increasing pressure to reduce hardware prototypes more and more validation is carried out with virtual prototypes that are not put together like physical prototypes and therefore cannot reveal important issues right away. Rather, validating a virtual prototype implies the need to know issues from the past so that the engineers validating a product can inspect the virtual prototype accordingly. Complex questions during validation such as "What implications on production processes would be incurred if we used a different blank thickness in car body design?" would resemble such a typical situation.

In order to make this new paradigm work we need to first digitize older knowledge and second find a way to make it accessible efficiently.

With the increasing pace of business (faster processes, increasing fluctuation among employees) less time is available to find missing vital information for the task at hand.

The classical idea of connecting IT-systems by interfaces that are hard and expensive to develop, to maintain and sometimes to even redesign may have worked in the past but cannot catch up with the increasing speed and complexity of today`s engineering processes. In fact, today it is not uncommon that business processes in general are expected to happen in real time. Hence new and more sophisticated IT-tools are needed guiding the user through the complex information landscape to find the right knowledge in acceptable time.

THE BMW-APPROACH: KNOWLEDGE FINDER

Business Context

The principle ideas of the Knowledge Finder originated from a close collaboration between business (department in charge of the car validation process) and IT while creating a new form of review method in order to detect issues early on in a car development project. During the first pilot of the new review method it became evident from the beginning that the method stimulated the open flow of knowledge among the participants across all disciplines. Though, as it has been noted evaluating the first reviews, the flow of knowledge couldn't be captured for future usage. In other words knowledge was elusive and the immediate question was whether this knowledge could be easily captured by a knowledge database. Soon it became clear that creating a new knowledge database was not the right answer to the challenge at hand for a number of reasons:

 The creation of a new data source would have meant to implement a very challenging, if not impossible, change management task considering the vast amount of business processes that would have to be changed in order to store data into the new database rather than using the existing data sources  Further it would have meant to create a new silo of information in addition to the existing ones that still continue to contain very valuable information  It would have been totally unclear at what point in time the amount of "new information" would have reached a sufficient level so that the users would have reaped a benefit tapping into the new knowledge database compared to the existing data sources

Hence the fundamental design decision for the Knowledge Finder came to rest on three pillars (see fig. 2):

 Reuse of existing data sources rather than creating an additional new knowledge database  The idea of Knowledge Finder acting as an agent networking in the "community of data sources" similar to a human that networks among his coworkers  Exploitation of "state of the art"semantic search technologies in order to follow a user-centric approach and to create an intuitive and "fun to use"tool to find knowledge rather than search for it Applying the fundamental design of the Knowledge Finder to the new review method mentioned before the following description of one of its main use cases could be described as follows  The discussion in a review session stalls because a vital piece of information/knowledge is needed and none of the participants knows this piece of information  The Knowledge Finder is triggered in order to answer the question "What (else) do we know about the issue being discussed?"  The Knowledge Finder taps into all available data sources as a single access portal and presents its findings in a user friendly form thereby harnessing the flood of information  The participants of the review either obtain the missing information at once or at least get a clue in which direction they should proceed with their discussion

Exploration of the idea

With this fundamental design idea in mind it was decided to apply a stage gate innovation management process to explore the potential of the Knowledge Finder while keeping risks at a minimum at the same time.

A steering committee consisting of business and IT managers across development and production department alike was formed to decide at each stage whether to proceed in the process or not (see fig. 3).

Fig. 3. -Stage gate innovation management process

The stage gate innovation management process was carried out as follows  First a proof of concept was carried out with the intention to find out whether the idea of the Knowledge Finder would really create additional business value and would be accepted by the users. Note here that at this point a truly business-centric approach has been followed. No data sources were connected to the Knowledge Finder online in order to avoid efforts considered as too risky at this early stage.  After an initial research for possible solutions a list of six IT-partners was compiled by a very small core team and proposed as participants in a first "Proof of Concept" (PoC) to the steering committee, which approved the selection for the PoC.  Once the findings of the PoC in terms of additional business value and user acceptance turned out to be very positive, the steering committee approved the proposal to proceed with a pilot phase where eight different data sources (structured data bases and unstructured data on a file server) should be truly connected to the Knowledge Finder.  The core team then selected three IT-partners to be invited to the bidding process for the pilot solution. The winner of the bidding was then contracted to implement the Knowledge Finder as a pilot.  Again the results of the pilot proved to be very positive and corroborated the earlier assessments of the Knowledge Finder. The steering committee consequently approved the proposal to proceed with the so called "transfer phase" which was intended to fulfill all the prerequisites for a formal proposal to initiate an IT-project to implement a productive solution.

IT-architectural considerations

While progressing along the stage gate process we also noted quite early on that the market for semantic search technologies is highly dynamic, i.e. the solution that seems appropriate today may not be the appropriate solution anymore in the future. Therefore we established two guiding principles:

 The solution we chose for the pilot would not necessarily be the natural choice for the prioritized IT-project, rather we would again look for the best suited solution available on the market by the time the IT-project would have been started  The solution architecture must provide for the possibility to exchange the core semantic search technology while leaving the connectors to the various data sources unchanged (see fig. 4).

We designed a strict decoupling of the semantic engine together with its search index and the data sources with the corresponding crawler database views, such that at any future point in time the single investments in setting up the database views remain protected while the semantic engine is changed over to a new technology. Furthermore we decided to decouple the application "Knowledge Finder" from the semantic engine such that other applications can reuse the semantic engine and the underlying search index for their purposes. This way we can both provide a semantic extension to a search engine inside a legacy system or provide other (new) applications (e.g. applications that have a focus on categorizing information) in need of semantic information processing with a common platform.

In fact, while being in the transfer phase another department (lab technology) requested to pilot the Knowledge Finder in order to assess possible improvements for their business process. And indeed, looking again at the market we found that a different solution provider could offer more added value to our Knowledge Finder (2.0) (see Table 1), which has been contracted for our second pilot. Given the search term "Plastik" Knowledge Finder 2.0 returns hits such as "Kunststoffanbauteile" and "plastic" demonstrating the capability of a semantic and bilingual search.

In addition Knowledge Finder 2.0 also extracts information objects such as "GS 97045-2" from free text, which denotes a so called "group standard" used at BMW that is mentioned within a lab technology report.

KEY FINDINGS

The two successful pilots resulted in a number of very interesting findings and observations which are outlined in the following sections.

User Experience

The possibility to ask a variety of different systems in a single consistent way rather than filling out different clumsy query interfaces obeying the internal data base schema was very well received by the users. The Knowledge Finder's interactive and intuitive interface enables a search process where the human brain and the search engine work together in finding the best hits thereby also avoiding the "Google-Syndrome" of obtaining thousands of hits that a user is incapable of dealing with. In fact it has been found from a cognitive information processing point of view that it is much easier for the human brain to start with a single search phrase first and then to successively add more search phrases thereby reducing the number of hits very fast.

It has been found empirically that in the vast majority of cases the user could reach a list of less than 20-30 meaningful hits with no more than three steps (either adding another search term or selecting a filter value)

Apparently the list of found knowledge matching the first search term stimulates the brain to pick the next search term by association. There is no need for the user to come up with more or less complicated boolean expressions to define the search, which in many cases cannot be stated anyway in the first place since the user is not necessarily 100% clear about what he is really searching for in the beginning.

New Opportunities

Finding experts on specific issues has become much easier than before as the Knowledge Finder helps employees and organizational units alike in extending and strengthening their networks.

Particularly in light of the increasing fluctuation of employees this opportunity cannot be valued highly enough, because for a knowledge worker it is essential that the cost of obtaining missing information is minimized.

The Knowledge Finder allows to ask questions or at least to explore possible solution spaces which has not been an option before because of the high hurdles to retrieve information hidden in all the various data sources.

Another new opportunity that the Knowledge Finder may offer is the possibility to address the challenge to put all information islands together mentioned by Randy Mott, CIO of General Motors in [START_REF] Bongard | Interview with Randy Mott[END_REF] (see also introduction). By pulling information from various data sources together into one single search index, the Knowledge Finder might open up a new road to circumvent all the challenges and problems of classical tedious system interfaces, such that the search index could be viewed as a new form of information bus.

Challenges

Of course, piloting the Knowledge Finder has revealed a number of challenges, some of which could very well be characterized as fundamental in terms of how do we manage information as a very valuable asset in a large enterprise in general. Within the scope of this paper three aspects of managing large quantities of information (quality, protection, and comprehension) shall be addressed and explained briefly why they are important.

Quality of Information.

It is common knowledge that for a communication to be successful it is necessary that sender and receiver have the same understanding of coding and interpreting information. If for example the German word for "expanding rivet" is written incorrectly in the data source (i.e. "Spreitzniet" instead of "Spreizniet") then that piece of information is not found when entering the correct spelling even drawing upon semantic search technologies. In fact during the lab technology pilot we both found hits when searching for "Spreitzniet" (incorrect spelling) and searching for "Spreizniet" (correct spelling) but the sets of hits were disjoint! In much the same way no semantic search technology today would be able to discern a variety of different ways to abbreviate (longer) words within free text (e.g. "homologation" = "hom." = "homol." = "homolog.").

Most search engines today include a spell checker with the auto suggestion function when entering a search term but they cannot cope with misspelled words in the data sources. Even worse, a spell checker applied to "Spreitzniet" would change the search term to "Spreizniet" thus missing (possibly) the most valuable information hits associated with the misspelled word "Spreitzniet".

Another type of lacking quality in information showed up in our first pilot. One of the test users turned very excited when he found a long missing Powerpoint-document only to turn disappointed when opening the document and discovering that its content didn`t match the search term at all. After a short investigation of this "false positive hit" it became clear that the meta information of the Powerpoint -document did match with the search term but by no means coincided with the content. What happened was, that (and that is typical) the Powerpoint-document originated from a template whose author and title had not been changed appropriately by the author of the found Powerpoint-document.

From a more general point of view the root cause of these observations can be explained by taking the approach that we are actually dealing with a flow of information.

With regard to a flow of material there exist a number of quality assurance techniques such as value stream analysis, (Ishikawa) fishbone diagrams or the application of Poka-Yoke principles in order to prevent wrong assembling of parts. For flows of information however, we do not possess corresponding quality assurance techniques nor have we transferred and adapted the well proven techniques for flows of material to flows of information.

One possible approach to do so could be to apply the so called DMAIC -cycle known from the six sigma toolset as indicated in [START_REF] Schmidt | Systematisches DQ-Management: den Daten bloß nicht immer hinterherlaufen[END_REF] and [START_REF] Schmidt | Der DMAIC-Zyklus für ein systematisches Datenqualitätsmanagement[END_REF]. However this is quite a generic practice which would lack specific tools in our context.

One such tool or best practice could be that the moment information is originally entered into any data source a spell checker automatically corrects input. This way we would also apply one of the lean production best practices known as "responsibility on site", meaning that any error that might occur should be corrected instantaneously right at the location where it occurred.

Protection of Information.

Naturally the idea of an all encompassing semantic search that links across various data sources triggers concerns with regard to intellectual property protection. In fact, in almost all data sources rules are in place to discern users that are allowed to read particular information from users that are not. Today it is common practice to grant (read) privileges on a "need-to-know-basis". However, we have found throughout the pilots that this principle has a number of disadvantages, of which some are listed below  Once a read privilege is granted on a personal basis in most cases it will never be removed, i.e. the read privilege might still be in place even though the personal need is not given anymore  Granting privileges on a need to know basis can be tedious, in particular if the number of information objects to be protected or the number of users is large. (we came across a situation where about 800 different folders on a file server needed to be overseen resulting in a full time job to do all the administration)  Typically read privileges on a file server can only be granted at the level of folders.

Hence if we grant read privileges to allow a user to read a particular file in that folder we inadvertently give read privileges to other files residing in the same folder for which that particular user should not have read privileges.  Last but not least the responsibility to grant any kind of privilege does not lie with the owner of the information object but rather with the (system) administrator, who even might not be employed by the enterprise Therefore one of the key findings of the pilots was to propose a different principle to protect information which we call the "need-to-protect-principle". With this principle we strengthen the role of the information owner in the first place. The basic idea is that the information owner decides whether a certain piece of information can be read by anyone within the enterprise or shall only be visible to a restricted circle of users.

In the latter case this information is not even presented to the Knowledge Finder, i.e. it is never been indexed and therefore cannot be found at all. If, on the other hand, certain information can be read by anyone inside the enterprise then a fair balance of interests can be established between the urgent need to share information for better collaboration within the enterprise and the need to protect (strictly) confidential information.

As a consequence the unproductive efforts of granting read access on a need-toknow-basis are minimized if not eliminated.

Finally applying semantic technologies it is well conceivable to scan documents in order to help classify them into the right protection level.

Comprehension of Information.

Piloting the Knowledge Finder we soon discovered that extending the scope of data sources beyond those known to the user (compare fig. 1) it is likely that users might get overloaded with the sheer number of information objects and their interdependencies.

In other words the Knowledge Finder gives rise to unveiling the complex information landscape that we inherently create while progressing within our product development process today.

First of all, making interdependencies in a complex product (recall [START_REF] Siemens | Herstelleralbtraum: Ein Produkt mit Funktionsfehlern[END_REF] in the introduction) visible is e.g. highly advantageous to an engineer who needs to validate a complex function of a complete vehicle and cannot do this anymore because he is lacking a physical prototype.

On the other hand (see fig. 6) it is questionable whether such a complex information landscape is always correctly mapped to the user`s brain so that the user is having the correct understanding of all the information and thus being able to draw the right conclusions.

CONCLUSIONS

In this paper it was shown how the increasing need to find buried information more efficiently again has led at BMW to the development of the Knowledge Finder and what road has been chosen to do so. During two pilot phases in two different disciplines (domains) many very valuable findings have been collected that influence the design of the next evolution of the Knowledge Finder for productive use.

In order to address the challenges mentioned before (quality, protection and comprehension of information) further research is necessary resulting for example in advancements with respect to semantic technologies.

As far as the aspect of comprehending complex information landscapes is concerned it is believed that new cross-discipline input from cognitive psychology and neuro sciences is needed in order to answer the following two questions.

 What is the appropriate design of new man-machine interfaces such that a minimum level of stress is imposed on the user when exploring complex information landscapes?  What is the appropriate design of new user trainings so that the brain can comprehend complex information landscapes better?

These questions cannot be addressed by computer science alone. Rather an interdisciplinary approach together with cognitive psychologists and neuroscientists is needed that could even lead to a new branch of computer science that might be called "Psycho-Informatics" in the future much like "Bio-Informatics" today. Such an interdisciplinary approach should look at new forms of interaction with information landscapes that go beyond the currently prevailing paradigm of interacting with information by screen, keyboard and mouse clicks.

It shall also be noted here that the further development of the Knowledge Finder will be a continuous ongoing process with adding more data sources and functional improvements and the design of the user interface step by step. We aim actually at offering the Knowledge Finder and its steady improvements as a service rather than rolling out software releases from time to time.

The idea is "Finding knowledge as a service" where suggestions from our users are added in an agile manner.

Fig. 1 .

 1 Fig. 1. -The Threefold way of categorizing potentially available knowledge in a large enterprise

Fig. 2 .

 2 Fig. 2. -The fundamental design idea of the Knowledge Finder

Fig. 4 .

 4 Fig. 4. -Basic IT-Architecture of the Knowledge Finder

Fig. 5 .

 5 Fig. 5. -Features of semantic search

Fig. 6 .

 6 Fig. 6. -Complex information landscapes vs. processing capabilities of the human brain

Table 1 .

 1 -The evolution of the Knowledge Finder Figure 5 below gives an overview of what is possible with today's available semantic search technology.

Translation by author: "Books that have already been read are not as valuable as those unread. A library should always contain as much of those things not known to its owner as the owner can possibly shelve into his library according to his financial abilities"


Arnulf Fröhlich

Josip Stjepandic
email: josip.stjepandic@opendesc.com

Christian Emmer

Advanced Engineering Visualization with Standardized 3D Formats

Keywords: Christian Emmer, Engineering Visualization, Interoperability, Data Exchange, JT Standard, Supply Chain, Engineering Collaboration

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

INTRODUCTION

Although the CAD translation technology has gathered a high level of maturity and robustness, there is still a strong need for further development driven by crucial business processes like digital mock-up (DMU) which is established as core validation process in the past years. Furthermore the CAD models have already exceeded the level of complexity, where they are easy to handle with. Meanwhile various 3D visualization formats have entered the market on the broad front by combining the high information content with easy handling and excellent performance. Thus these formats can support many process chains from styling to product simulation, validation and production as well as downstream life cycle phases. By the extensive penetration of visualization formats in the market the old discussion was reopened, whether the unique format can fulfil the requirements of the engineering collaboration (internal and external). Finally the users need the recommendation too, which format meets their needs in the best way [START_REF] Emmer | Digital Engineering Visualization, SASIG, SASIG Guideline[END_REF], [START_REF]Collaborative Product Visualisation -General issues and use case description[END_REF]. Typical use cases for functional evaluation of such formats are the viewing of engineering data, the design in context, the data exchange between partners in the supply chain, the packaging and digital mock-up (DMU), the documentation and archiving, and use in the portable PLM document, i.e. use of 3D and additional information in domains related to engineering (Figure 1). After the rough evaluation of the technical specification of the visualization formats an overall comparison can be drawn [START_REF] Fröhlich | White Paper 3D Formats in the Field of Engineeringa Comparison[END_REF] (Figure 2). [START_REF] Fröhlich | White Paper 3D Formats in the Field of Engineeringa Comparison[END_REF].

Fig. 2. Comparison of four visualization formats

However in the automotive and aerospace industry JT from Siemens PLM is currently under heavy investigation to apply it in downstream processes after it was established as leading format for the engineering visualization in many global companies [START_REF] Biahmou | Universelle Formate für Visualisierung und Konvertierung in der Engineering-Kollaboration[END_REF]. For instance, there is the demand to exchange exact geometry, product data information and additional attributes. Moreover JT is also a potential data format for long-term data retention. Consequently, there is high user interest in quality and robustness of the applications, the interfaces in particular. Thus the further explanation in this paper will be focused on JT although other formats (STEP, 3DPDF, 3DXML) are in the different stages of standardization procedure.

Open standards enable reduction of total costs of ownership and ensure independence from specific vendors and competition. With regard to visualization data exchange there is a strong support to use JT and STEP AP 242 (ISO 10303-242) as complementing standards for lightweight visualization format for 3D industrial data as well as product structure, meta, kinematic data [START_REF] Handschuh | Wertextrahierende Nutzung von offenen leichtgewichtigen Datenformaten in automobilen Kollaborations-und Entwicklungsprozessketten[END_REF].

The publication of the JT specification as an ISO Publicly Available Specification (PAS 14306) laid the foundation for establishing JT as a binding process format. The ProSTEP iViP Association and the VDA (German Association of the Automotive Industry) subsequently launched three coordinated JT-specific projects: the JT Workflow Forum, the JT Implementor Forum and the JT Application Benchmark.

TECHNICAL BACKGROUND AND STANDARDIZATION

JT is a binary format whose data model supports various representations of CAD geometry. The representations can be stored in a JT file individually or together [5] [6].

 BREP (Boundary Representation): Offers the highest level of representational precision. BREP data is compressed using different algorithms and stored without loss. In the current specification 9.5, two BREP representations are permitted: the traditional JT-BREP representation and XT-BREP, which is based on the Parasolid boundary representation and will be preferred in the further implementation of JT based software.  Tessellated Geometry: A faceted representation of solids and surfaces. Different levels of detail (LOD) can be defined within a JT file. A low LOD means a lower level of precision but a smaller volume of data, while a very high LOD means an almost exact geometry but a large volume of data.  ULP (Ultra-Lightweight Precise): The latest compression method is ULP. The ULP format enables a lightweight, semi-precise representation of the 3D geometry.

The level of precision that ULP offers is significantly higher than for tessellated geometry while the file size is significantly smaller. The primary focus lies on providing high quality surface geometry that exhibits only minor deviations from the original BREP geometry.

JT version 8.1 has been initially published by the ISO as a publicly available specification (ISO PAS 14306). The ISO standardization process has been finished by endorsing the ISO standard (ISO 14306) in December 2012 for the recently published JT version 9.5, which has been expanded to include the specification for ULP and semantic product manufacturing information (PMI, product metadata) among other things.

Generating data in a neutral 3D format results in most use cases with a significant reduction in volume. In order to compare the file size of the 3D formats, fifteen test assemblies from different CAD systems were used to generate different 3D formats [START_REF] Handschuh | ProSTEP Symposium 2012: JT on the Path of Enlightenment -Report of the JT working groups[END_REF]. As a result the volume of data is determined more by data content then by the format itself.

The volume of exact BREP data after conversion to JT is approximately the same as after conversion to 3D PDF. The same applies to tessellated content, where the result for both formats is about the same as for 3D XML. In the case of simplified BREP data, the volume of data for both JT and 3D PDF are approximately the same. In the case of STEP data, use of an external compression algorithm achieves a marked reduction in size. As a consequence higher accuracy requires more storage space as a general rule.

USE CASES

An evaluation of the 22 use cases defined by automotive manufacturers and their suppliers indicated a particularly high priority for four use cases, which are presented below in more detail by way of example [START_REF] Handschuh | ProSTEP Symposium 2012: JT on the Path of Enlightenment -Report of the JT working groups[END_REF] (Figure 3). Fig. 3. Use cases for simplified formats [START_REF] Handschuh | ProSTEP Symposium 2012: JT on the Path of Enlightenment -Report of the JT working groups[END_REF].

Viewing: If the use of a CAD system is not desired, the visualization of engineering data using 3D viewers comes into play in a number of different situations: the presentation of product data, the representation of 3D models for information purposes (e.g. for a design review or marketing) and the realistic representation in virtual reality systems.

The use case can vary according to the concrete application context involved. While the simple viewing of the geometry is sufficient in many cases, in other cases metadata or high-performance viewing of huge assemblies plays a key role. The most important requirements are:

 Quality criteria for geometry accuracy must be fulfilled.  Different level of details must be available.  Detailed colour information must be available for entire part and single geometrical features.  Metadata like attributes must be stored.

Packaging / DMU: In digital mock-up (DMU), the spatial properties of a product are examined and checked. This can involve checking the overall geometry with regard to dimensions and shape, interference checks, collision checks for assembly and disassembly, as well as design space checks (Figure 4).

For these purposes, the geometry, product structure and metadata are displayed and analyzed in a DMU application. The result of the DMU analysis is subsequently summarized and documented in a report. The most important requirements are:  Use of models from different source systems (multi-CAD).  High-quality examination of large assemblies.

 Transferability of kinematics from the original model to the target model for dynamic DMU analysis. Design in Context: A typical used modeling method is the design in the context of the existing geometry. In that case existing CAD models (e.g. from previous design or from partners) are loaded into the CAD system. The design engineer then references new or existing JT-geometry to the loaded parts or assemblies. References from native CAD to JT are also in focus. These references can be between auxiliary geometry (point, axis, plane), geometrical elements such as edges, vertices or faces and exact geometrical references like curves. In the subsequent downstream processes it is required to use this assembled model as merged single unit. Hence the creation of technical drawings must be possible. The most important requirements are:

 Tessellated as well as exact B-Rep data must be stored.  Links between JT and native data must be possible.  Technical drawings must be derivable from hybrid models.

Partner Integration: The use case is divided into two sub sections. The aim of the "OEM to Supplier" use case is to send validated JT geometry with all needed metadata to the supplier, whereas the "Supplier to OEM" use case defines the exchange of JT files to the OEM. Common to both sections is that the use cases provide a basis for further use cases. This means that by the Supplier or the OEM more specific use cases (viewing, design in context, etc.) will be applied subsequently. The most important requirements are:  Quality check of JT and validation against native CAD model.  Meta data must be contained in JT model.  Removal of intellectual property (if necessary).

EVALUATION AND TESTING

An important aspect in driving the application and development of JT is a coordinated approach between the different bodies on the one hand and a coordinated approach of the activities themselves on the other hand.

DMU

Involved Bodies

Basis for the standardization activities of JT were the enormous efforts of many international bodies. After the initial impact has be accomplished by SASIG [START_REF] Emmer | Digital Engineering Visualization, SASIG, SASIG Guideline[END_REF], the four bodies ProSTEP iViP Association (PSI), the German Association of the Automotive Industry (VDA), the Automotive CIO´s and the Global Automotive Advisory Group for PLM (GAAG) have played a leading role (Figure 5). Therewith ProSTEP iViP (www.prostep.org) has driven the activities thoroughly. Last but not least the MoU (Memorandum of Understanding) between Siemens PLM und ProSTEP iViP provides the basis between both parties in the area of JT, in order to foster a common understanding of goals and measures to establish JT as binding process format.

National and International Coordination

In 2009 the ProSTEP iViP Association, in a joint effort with the VDA (German Automotive Association), has started three different but interacting world-wide unique JT activities. Within the so-called JT Workflow Forum Use Cases for the application of JT are specified, describing the common view from industry. The JT Implementor Forum provides support in JT translator development maintains a platform for interoperability testing for the vendors. Within the JT Application Benchmark the requirements are comprehensively tested within neutral environment. The project plans of these three project groups are well-harmonized, for driving the application of JT as a common effort.

JT Workflow Forum: Aim of the project is to define and prioritize key use cases and to identify relevant downstream processes for the JT based data exchange. For all use cases requirements are collected and test criteria defined e.g. under the aspects of exchanging of visualization data, the validation of 3D geometry, GD&T (Geometric Dimensions and Tolerances) and last but not least translator quality.

These tasks are supported by the Content Harmonization subgroup, which is responsible for providing a clear definition of which requirements should be satisfied by the JT format and which by STEP AP242 as backbone format.

JT Implementor Forum: Within the framework of the JT Implementor Forum Project Group, a platform for interoperability testing for the vendors is maintained. It is a forum where participating vendors can test the translators that they are developing "behind closed doors". The JT Implementor Forum is a neutral forum for software vendors, where they can perform tests in an atmosphere of mutual trust and exchange information on experience already gained.

In addition, from the vendor perspective, the activities within the JT Implementor Forum can be seen as a kind of preparation for the JT Application Benchmark.

JT Application Benchmark: Based on the recent standardization activities of JT and also STEP AP 242, it is of importance to assure data exchange quality within a neutral Benchmark and to provide support in JT translator development.

The ProSTEP iViP Association, together with the VDA PLM working group, has initiated a first JT translator benchmark in 2009. Subsequent the second translator benchmark was conducted in 2010. The third benchmark was completed by the end of 2012. Thereby the focus will be laid on three main topics:

1. CAD to JT export, focus on LOD and PMI. 2. JT viewing, focus on performance and functionality 3. Assembly conversion with STEP AP 242 XML and JT Vendors participating in the benchmark are invited to present their latest functionalities in form of Showcases to the JT Workflow Forum members. In focus are cuttingedge solutions that demonstrate the possibilities of the JT format and applications. There are still small functional errors and therefore need for improvement (Figure 6).

PILOT PROJECTS

As a further step towards the productive usage of JT in automotive downstream processes, first pilot projects are established. Volkswagen decided to use JT for internal downstream processes to eliminate the need for drawings [START_REF] Handschuh | ProSTEP Symposium 2012: JT on the Path of Enlightenment -Report of the JT working groups[END_REF] [8] (Figure 7). This application is limited to the use case "single parts" and shall be subsequently extended to the full assemblies to avoid the usage of huge JT monolithic files. In the following the process landscape (Use Case: "Supplier to OEM") of the Daimler/Continental JT-pilot project is shown (Figure 8).

In order to fulfill the OEM needs (e. g. in case of data quality) it has to be ensured that the JT and the accompanying structure formats are created properly. In a first step the configuration settings of the JT-translator have to be adjusted to the OEM needs. Therefore the mentioned ProSTEP iViP JT Content Harmonization workgroup (JTCH) has created a first best practice document [START_REF] Prostep Ivip | Whitepaper Applying JT -Guidance for Using JT in Practice Version 2[END_REF]. In the second step, the OEM specific data preparation has to be done. Therefore the Daimler JT Supplier Package (JTSP) is available for all Daimler suppliers [START_REF] Handschuh | ProSTEP Symposium 2012: JT on the Path of Enlightenment -Report of the JT working groups[END_REF]. The Daimler JTSP offers the opportunity to edit the JT internal attributes and to prepare XML based structure formats to meet the OEM requirements. The third step in the process landscape is the data exchange to the OEM. In case of the Daimler AG the OFTP based SWAN system is used.

The final step of this process is the data import into the Daimler PDM system Smaragd. At this point in time the externally created JT datasets are released and available to all Daimler downstream processes such as Viewing, DMU or Design in Context [START_REF] Handschuh | Standardized formats for visualization -application and development of JT[END_REF].

Meanwhile the full CAD data exchange by using JT is going to be adopted as base CAD translation technology by supplier portals like OpenDESC.com (www.opendesc.com) [START_REF] Bondar | Globalized OEM and Tier-1 Processes at SKF[END_REF].

CONCLUSIONS

This contribution addresses the state of the art activities in in order to establish JT as an universal process format. Industry needs simple solutions for the efficient use of IT technology inclusive consistency in processes. There are strong requirements for lightweight 3D formats for the visualization and downstream processes, complementary formats in order to exchange meta data, structure data and kinematics data as well as open and standardized formats to reduce total cost of ownership and to minimize dependency of single vendors [START_REF] Röhl | Einsatz des JT-Formates in der Digitalen Fabrik[END_REF], [START_REF] Prostep Ivip | Whitepaper Applying JT -Guidance for Using JT in Practice Version 2[END_REF], [START_REF] Handschuh | Standardized formats for visualization -application and development of JT[END_REF]. After these very promising pilot projects mentioned above the activities on the subject of lightweight visualization based on JT have already reached a good level of maturity encouraging the wide range of companies and users, whereas it is a forthcoming task to push the integration with the accompanying format STEP AP242 (Figure 9). However first applications creating or using STEP AP242 XML as a out-or input format are already available today, the wide usage will be announced in the next years. The future data exchange process will adopt JT as well as STEP AP242 ensuring the exchange of whole complex products in all stages of product and process development (Figure 10).

Fig. 1 .

 1 Fig. 1. Typical use cases of JT [1].

Fig. 4 .

 4 Fig. 4. -Use case diagram "Packaging".

Fig. 5 .

 5 Fig. 5. -International cooperation in the standardization of JT.

Fig. 6 .

 6 Fig. 6. -Results of recent JT benchmark

Fig. 7 .

 7 Fig. 7. -Usage of JT within the Volkswagen Group

Fig. 8 .

 8 Fig. 8.-Usage of JT in partner integration[START_REF] Handschuh | ProSTEP Symposium 2012: JT on the Path of Enlightenment -Report of the JT working groups[END_REF]

Fig. 9 .

 9 Fig. 9. -The schedule of JT and STEP AP 242

Fig. 10 .

 10 Fig. 10. -Assembly data exchange with JT and STEP AP 242