iDMU as the Collaborative Engineering engine Research experiences in Airbus

Fernando Mas, José Luis Menéndez, Manuel Oliva PLM Process & Tool Solutions Department

Airbus Defence & Space Sevilla, Spain

fernando.mas@airbus.com

José Ríos, Alejandro Gómez, Víctor Olmos Mechanical Engineering and Manufacturing Department

Polytechnic University of Madrid Madrid, Spain

jose.rios@upm.es

Abstract—Collaborative Engineering aims to integrate both functional and industrial design. This goal requires integrating the design processes, the design teams and using a single common software platform to hold all the stakeholders contributions.

As a result of a virtual manufacturing project for the A400M Final Assembly Line (FAL), Airbus Military coined the concept of the industrial Digital Mock Up (iDMU) as the necessary unique platform to deploy Concurrent Engineering. Along 2013 Airbus Military has developed another research project, named CALIPSOneo, to implement an iDMU for the industrialization of the A320neo fan cowls.

The implementation confirmed that the iDMU concept is feasible as the basis common platform for the development of an aerostructure.

The experience and knowledge, derived from working in the implemented iDMU, allow concluding that the iDMU can be the engine empowering the Collaborative Engineering paradigm and additionally, it can be extended to comprise the entire product lifecycle.

Keywords—Collaborative Engineering, iDMU, PLM, Virtual Engineering, Process Simulation

I. INTRODUCTION Since 1999, starting with the A340 program, Airbus has

applied Concurrent Engineering practices to several aircraft design programs: C295, A380, A400M, and A350 [1-4].

In the last ten years, virtual manufacturing techniques are used for the industrialization of aircraft assembly lines, and also as an enabler of the Concurrent Engineering endeavor. The product Digital Mock-Up (DMU) is considered as a strategic element supporting the implementation of Concurrent Engineering practices, “DMU as master” approach (Fig.1) [5]. In this period, the model of Concurrent Engineering has also evolved at the same pace as the information technology and PLM tools to become the currently called Collaborative Engineering [6]. The Collaborative Engineering approach integrates sociological and technological aspects, aiming to achieving that a set of engineers actively and rationally participate in a consensual joint decision making process, supported by a computer based collaborative environment [6].

Within Airbus, the greater obstacle for this evolution is that the development of the aircraft is carried out by separated

processes. Where functional design, industrial design, design of services and related processes are supported in separated engineering systems: PDM, Virtual Manufacturing tools, Jigs & Tools (J&T) design and different authoring systems for shopfloor instructions and services documentation [3-4].

Consequently, to progress in the implementation of the Collaborative Engineering, it is necessary to increase the degree of integration of the processes involving functional, industrial and services design. This should allow getting the maximum possible feedback among them, to obtain an optimal design of the aircraft not only in the functional aspect, but also in the industrialization and service ones. Additionally, this requires that all the processes of the aircraft development are carried out by a common team and under a common software platform shared by all the stakeholders.

This conclusion of the need for a common collaborative platform is confirmed by the PLM community. PLM experts and users share a common understanding on the necessity of solutions that facilitate easy, ubiquitous and fast sharing of product, processes and resources information across the entire product lifecycle and among all the actors involved [7-10].

The development of solutions, to facilitate the implementation of both the concurrent engineering and the collaborative engineering in the aerospace sector, was the objective of some projects since the end of the 1990’s decade. Two of the most relevant ones are the European projects ENHANCE [11] and VIVACE [12].

The ENHANCE project, focused on the Concurrent Engineering approach, started in 1999, comprised up to forty nine partners, including first level suppliers, and its aim was to enhance the business processes, information management, information technology infrastructure, working methods and the integration of the supply chain [11].

The VIVACE (Value Improvement through a Virtual Aeronautical Collaborative Enterprise) project started in 2004. It used as input the results derived from the ENHANCE project but pursuing a Collaborative Engineering approach [12]. VIVACE was focused on the aircraft development cycle and the propulsion system. It aimed developing the tools needed to create a collaborative environment to facilitate the knowledge engineering, the objective oriented design, the information management and the extended enterprise integration [12].

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The mentioned projects are characterized by being focused on the aircraft functional design engineering, leaving the industrialization design engineering out of their main scope. The main European aerospace companies participated in such projects, and to some extend it helped them to implement the concept of ‘DMU as master’ [1].

In this context, Airbus has not limited itself to be an end user of Virtual Manufacturing and PLM tools, but it has worked to build and spread a body of knowledge and methodology related to such techniques [1-5, 13-16].

Fig. 1. Concurrent versus Collaborative approaches: “DMU as master” versus “iDMU for all”

Unlike the mentioned projects that left the industrialization design in a secondary place, but with a smaller scale of action, the A320 CALIPSOneo project was launched by Airbus to promote the Collaborative Engineering by implementing the industrial Digital Mock-up (iDMU) as a way to help in making the functional and the industrial designs evolving jointly and collaboratively.

The iDMU concept is the approach defined by Airbus to facilitate the integration of the processes of the aircraft development on a common platform throughout all their service life. An iDMU gathers all the product, processes and resources information, both geometrical and technological; to model a virtual assembly line. An iDMU provides a single environment, in which the assembly line industrial design is defined and validated [3]. Once the industrial design is completely verified and confirmed as free of errors, the result is an iDMU that contains all the necessary information for the automatic generation of the shopfloor documentation needed to execute the manufacturing processes [16]. As a step forward in the approach based on the “iDMU for all” (Fig. 1), the design of services could also be defined and validated in the same way as the industrial design, and after it, all the services documentation could be authored. This objective of incorporating product information that goes beyond the Beginning of Life phase, to include activities and services occurring in the Middle of Life and in the End of Life phases is still a research topic being address by the PLM community [17]. Fig. 1 illustrates the Concurrent versus the Collaborative approaches (“DMU as master” versus “iDMU for all”).

In the following sections, it is explained the process followed by Airbus to implement a virtual manufacturing

framework to execute a pilot implementation of the iDMU of a medium size aerostructure. The identified main barriers, the solutions adopted and the knowledge acquired out of this endeavor are also presented.

II. COLLABORATIVE ENGINEERING EXPERIENCES Collaborative Engineering (CE) is a socio-technical process

promoting that all the design teams work towards a common goal [6]. In Airbus, this requires that all the teams engage in a process of interchanging their different perspectives regarding the aircraft design. Along such process those different perspectives evolves until a common understanding about the aircraft design is reached [2].

To pursue that, the concept of CE in Airbus aims integrating the teams and the processes of functional and industrial design to produce a common unique deliverable, the industrial Digital Mock Up (iDMU) [3]. Figure 2 depicts an example of a 3D representation of an aircraft FAL iDMU, showing the product and the resources.

With such aim, an enabler, as it is widely acknowledge in literature [6-10], the intensive use of PLM tools is promoted. Especially Virtual Manufacturing is the key element to guarantee an aircraft functional and industrial design free of errors. At the end of the design process, the iDMU contains all the information regarding both functional and industrial design: 3D geometry and technological information. This way, the iDMU is the unique source of information for the later activities in the aircraft lifecycle, the “iDMU for all” concept [3]. In particular, the documentation for shopfloor can be obtained by exploiting the iDMU by means of virtual and augmented reality solutions [16].

Evolve the working methods from a concurrent approach to a collaborative one requires a progressive and permanent process, lead by the organization, supported by the personnel and facilitated by the technology. It is a challenging process, along which the A400M Final Assembly Line (FAL) project and the A320 CALIPSOneo project are, so far, the cornerstone of it. Next, both actions are briefly explained, pointing out the main contributions that helped to implement the CE concept.

A. The A400M FAL Project: the antecedent In 2003 Airbus began the detailed industrial design of the

A400M Final Assembly Line (FAL). It posed a difficult challenge, because the A400M military transport entailed some final assembly requirements very different from the ones demanded to the previous military transport. It was a larger and much more complex aircraft than any previous one. The monthly rate of three aircrafts was twice the previous ones. The concept of modular final assembly was also different from the previous concepts. To meet this challenge, Airbus considered that Virtual Manufacturing was one of the main solutions for designing the A400M FAL.

With that idea, Airbus launched a project to implement Virtual Manufacturing for the A400M FAL [3]. The two main aims of the project were to cope with the complexity of the industrial design of the FAL, and to leverage the concurrence with the functional design of the aircraft.

A platform based on Dassault Systemes PLM tools was implemented. This platform included CATIA V5 for the aircraft design and the Jigs &Tools (J&T) design, DELMIA V5 for executing Virtual Manufacturing simulations and a customized DELMIA V5 Manufacturing Hub to manage the process structure including all the metadata of each process and the processes’ precedence. The Airbus times system was implemented and a utility to optimize the sequences of the processes of each station was developed. Such development takes as input the information of times and precedences recorded in the process structure. In addition the DELMIA V5 finite events simulator QUEST was used to optimize the flow of the assembly line.

Fig. 2. Example of an aircraft FAL iDMU

New collaborative working procedures were defined to carry out the new process. A multidisciplinary team, composed of industrialization engineers and PLM tools experts, was assembled. Working procedures were defined to steer and assist the collaboration. Considering the professional profile of the personnel, the workload was distributed and specific training was provided. For instance, industrialization engineers, focused on the industrial design tasks, were trained to comprehend the way PLM tools could help in the industrialization design process. And PLM experts, with specific training in the virtual manufacturing tools, were responsible for creating the DMU and the simulations requested by the industrialization engineers.

The project provided a technological leap that can be resumed in the following points:

• The assembly processes were studied and defined in specific digital mockups of product and J&T. The more critical processes were validated by means of assembly and ergonomics simulations using DELMIA V5.

• Expensive J&T physical mockups were substituted for digital ones. The J&T were designed in context in specifics digital mockups of product for each resource with CATIA V5.

• The definition of the process structure, including all the metadata and precedences, was implemented in a single repository. The assembly sequences of each assembly station of the FAL were analyzed and optimized.

• The assembly line flow was simulated for different configurations, identifying the optimal solution for the ram-up and several production rates.

• A Virtual Manufacturing environment was deployed, including hardware and software platform, a virtual reality room and a group of PLM tools experts.

• The Virtual Manufacturing culture was introduced in the community of industrialization engineers.

• The concurrence with the aircraft functional design was improved. The industrial design of the assembly line was carried out in parallel with the aircraft functional design, both designs maturing at the same time. Thus, an early detection of problems of the aircraft functional design and the J&T design was possible when the correction of these problems still has little economical impact, avoiding its later correction by expensive procedures of design modifications.

• The Virtual Manufacturing environment was used to review the assembly processes with the shopfloor supervisors and to provide virtual training to workers.

Notwithstanding the previous advances, the accomplishment of the project and its later deployment, logically, did not solve the flaws of the concurrent engineering model. The processes of functional design and industrial design stayed separated and carried out by teams having different abilities and perspectives and often having opposed objectives. This issue fits within the interactive and separate decision style type described by S.C-Y. Lu et al. [6].

Another flaw of the concurrent model is the ‘product digital mockup (DMU) as master’ approach. Created in the process of functional design, using PLM tools, the product DMU is the source of all the product information for the rest of activities of the aircraft service life [5]. But the relevance of the product DMU decreases along the product lifecycle. For the industrialization tasks, the closer they are to the physical production of the product, the less they use the product DMU and the more they are based on paper. This could be a consequence of the lesser degree of attention that industrialization design received in the past within the concurrent and collaborative research initiatives.

After the project deployment, the functional design and the industrial design had still separated environments, but the industrial design process made use of PLM tools. The Virtual Manufacturing, the management of the process structure and the analysis of the assembly line flow were done in a not fully integrated environment. Virtual Manufacturing was made case by case. Each assembly process was studied and simulated separately, being necessary to build the DMU of the specific context of product and J&T for each process. The influence of the industrial design in the functional design consisted of feeding back information of manufacturing for the detection and early correction of problems.

Despite the improvement reached with the implementation of the Virtual Manufacturing practices in the A400M FAL project, it was necessary to continue advancing in the reduction of the still existing separation between the processes and

environments of functional and industrialization designs. That is, to evolve from the concurrent (“DMU as master”) to the collaborative (“iDMU for all”) paradigm.

As part of the implementation of the collaborative policy, Airbus undertook the A320 CALIPSOneo project.

B. The A320 CALIPSOneo project: the last experience This project is a joined effort involving Engineering

Companies, IT companies, PLM Vendors and Research Centers and Universities [4].

The project has comprised a real implementation of an iDMU for the industrialization of the A320neo Fan Cowl, a mid size aerostructure. It has encompassed the industrialization design by means of the Product, Process and Resources (PPR) context, including assembly work instructions and their deployment using augmented reality techniques. From the industrialization design perspective, it comprised a wider scope than projects dealing with 3D assembly simulation reported in the literature [18].

Fig. 3. Example of an iDMU in the DPM environment

Fig. 4. Example of an iDMU in the DPE environment

The iDMU implementation was made in CATIA/DELMIA V5. The iDMU was built by customizing the DELMIA V5 Manufacturing Hub [4]. The customized environment comprised the PPR context, which was accessible by means of

two user interfaces. A 3D geometrical interface: Digital Process for Manufacturing (DPM) and a database interface: DELMIA Process Engineer (DPE). Fig. 3 and Fig. 4 show an example of both environments respectively.

In terms of scope, this iDMU implementation was focused on the industrial design of the Fan Cowl, while the functional design was managed by means of the existing PDM platform. In order to maintain in the PPR context the product structure, an ad-hoc application was developed that periodically updates all the modifications released by functional design.

The Resources structure was populated directly in the PPR context. Each resource comprises its 3D design and metadata.

The Process structure was also populated directly in the PPR context. It comprises the FAL, station, assembly operation and task levels, each one with his corresponding metadata. In each level, each process includes the network of precedences between its children. As a consequence, the process structure is a collection of nested precedences networks. Each process also has assigned all the products that have to be assembled and all the resources that have to be used. Once the PPR context is structured in this way, the Manufacturing Hub is able to calculate the configuration of the digital mockup of product and resources that corresponds to each process, taking into account all the products assembled in the preceding processes, the resources used in the process and the resources that remain in use from previous processes. This capability of the Manufacturing Hub provides automatically for each process, in the 3D interface, the specific product and resources context, in which it can be analyzed, defined and validated by means of simulations (Fig. 5). Therefore, there is no more need to build, manually and case by case, the digital mockup of product and resources for defining each process and validating it by means of simulations.

This capability also makes possible to review, step by step, the execution of assembly processes, to select any process node as the initial process and to control the lower lever of the process structure to be executed.

Fig. 5. Static view of an iDMU assembly process context for simulation

Another capability provided by the Manufacturing Hub is the control of the assignations of product and resources to the processes. Colored flags in the 3D interface show if an element of product or resource is assigned to a process or not. This way,

the assignations can be controlled and elements pending of assignment can be detected.

Another capability of the Manufacturing Hub is to manage effectiveness, not only for product, but also for processes and resources. Thus the three processes, product and resources structures are configured ones.

The Manufacturing Hub is implemented on an Oracle database. Therefore, it can be customized by developing specific user utilities. The main developed utilities were the following:

• Airbus times system including the application of the training curve.

• Verification of the coherency of process, product and resources lifecycles based on sequence constraints between the maturities states of each element lifecycle.

At any level and for each process, the Manufacturing Hub makes possible to include assembly annotations and views to illustrate the shopfloor documentation. These views can include the assembly annotations and the design annotations included in the product elements. As a consequence, all the necessary information to create the shopfloor documentation is included in the PPR context. A sub-project of CALIPSOneo was dedicated to analyze the diversity of information that must be shown in the shopfloor documentation and the methodology necessary to include such information in the PPR context, as well as to make the developments needed for an automatic generation of the shopfloor documentation. A third sub-project developed the applications needed to deploy the shopfloor documentation by means of augmented reality in a tablet-PC.

As a result, the project CALIPSOneo has implemented one real iDMU comprising the complete process, product and resources structures of the A320neo Fan Cowl. In this iDMU was possible to deploy the complete cycle of definition and validation of several selected processes, and to obtain afterwards the corresponding shopfloor documentation. The achieved results confirm that the iDMU provides a common platform to carry out all the industrial design tasks and to record all its related information for the A320neo Fan Cowl.

III. THE A320 CALIPSONEO PROJECT RESULTS. The main result of the project was the creation of an iDMU

of a real aerostructure. Such result proves that the iDMU concept is viable and it can be implemented with current PLM tools.

The PPR context of the commercial software provides a generic data structure that has to be adapted for the processes and resources of each particular implementation. In this case, a specific data structure was defined to support the Airbus industrial design process, the process structure nodes, the resources structure nodes and their associated technological information, 3D geometry and metadata.

The Process structure comprised four levels represented by four concepts: assembly line, station, assembly operation and task; each concept has its corresponding constraints (precedence, hierarchy), its attributes and its allocation of products to be assembled and resources to be used. Once the

PPR structures were defined, the system calculated the product digital mock-up and the resources digital mock-up that relate to each process node. As a result, in the 3D context (DPM), the 3D context specific to each process node was shown to the designer. Then the designer created simulations to analyze and validate the defined manufacturing solution. This validation of the process, product and resource design, by means of Virtual Manufacturing utilities in a common context, is a key feature in the Collaborative Engineering deployment.

Once the process was validated, work instructions were created as part of the iDMU. Such instructions were used to create the shopfloor documentation. Ad hoc proofs of concept developments were created to generate shopfloor documentation with a basic level of automation and deployed by means of augmented reality.

Although in this case, it was not implemented, since it required an additional development to migrate the current PDM solution used by the company. The iDMU provides a suitable environment to carry out the Functional Design process. This option would allow a better collaboration with the functional design.

During the execution of the project, the reutilization capabilities of the iDMU were also tested. The information generated by the design activities, both 3D geometry and metadata, were available for task downstream in the lifecycle.

Hence, it can be stated that the iDMU provides all the necessary functionalities and features to be the unique deliverable defining the functional and industrial design of an aerostructure completely.

The software environment used to create the iDMU, Dassault Systèmes V5 (DS V5) commercial applications together with the ad-hoc developments, allowed eliminating the separation between different platforms for process, product and resources design. All the design activities could be done in a single environment, helping to eliminate the separation between design processes. All the design activities could be carried out in parallel but in a coordinated way, sharing all the information generated between them.

IV. CONCLUSIONS The implementation of the Collaborative Engineering

concept requires a progressive approach, where the organization, the people and the technological resources involved in the different processes evolve from the concurrent practices and state to the collaborative ones. In that sense, the execution of the A400M FAL project was a first step that created the basis for the later success of the A320 CALIPSOneo project.

Out of the implementation of the A320neo Fan Cowl iDMU and the knowledge derived from working in it, a main conclusion can be drawn: the iDMU is suitable as the single platform were the Collaborative Engineering socio-technical process can by carried out.

In the iDMU the perspectives of functional, J&T and industrialization design teams can be shared, challenged and validated, evolving until a common understanding is reached.

From the results, it can be concluded that the iDMU offers features and capabilities to leverage the Collaborative Engineering socio-technical process. The main ones are:

• The gathering of the process, product and resources designs in a PPR context, is a big enabler to share the diverse design perspectives, to discover errors hidden in each design, to show up the divergences between them and to facilitate the interchange between teams.

• The iDMU capabilities of information reutilization help to test and validate a greater number of solutions, thus improving the harmonization and optimization of the process, product and resources designs.

• The iDMU as a single environment for the aerostructure design facilitates that both the functional and the industrial design mature at the same pace greatly influencing each other.

The mentioned features support the iDMU as the engine empowering the Collaborative Engineering paradigm. But Collaborative Engineering deals not only with integrating processes and platforms. It aims also integrating the functional and design teams in a single team doing all the design activities. This has a large set of implications, not only technical, but mainly functional, which were not addressed in the conducted projects.

V. NEXT WORK As stated above, the A320 CALIPSOneo project focused

mainly in the implementation of an iDMU for the industrial design process. But the Airbus vision is that the iDMU must be the unique platform for all the activities along the aircraft lifecycle. To achieve that, more developments are needed in the following areas:

• The migration of current PDM functionalities into the iDMU, so the functional design could be carried out completely on the iDMU.

• To build in the iDMU the As Built product structure. This requires interfacing the iDMU with the ERP and MES systems to feedback into the iDMU the deviations of the manufacturing of the aircraft.

• To extend the iDMU scope to the Services function. Services engineers are also stakeholders of the product development and should be able to exploit the iDMU to design services and create service documentation.

• To extend the iDMU scope also to the external enterprise engineering providers. The supply chain is increasingly participating in the product development and also should be able to work collaboratively.

• The Manufacturing Hub is a DS V5 tool. It is worth to test how the iDMU could be implemented in a V6 platform and identify the gains that could be achieved.

ACKNOWLEDGMENT Authors wish to express their sincere gratitude to colleagues from Airbus Military, Universidad Politécnica de Madrid, Universidad de Sevilla and partners of CALIPSOneo project for their collaboration and contribution to the project.

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