Systems engineering and PLM
What is the Position of Dassault Systèmes?
The basis for this background article was a discussion with Marc Frouin, Senior Director PLM Systems Solutions Introductions, and supplementary explanations from the Dassault Systèmes expert Bernard Clark, Director of Marketing and Business Development PLM for Systems.
Marc Frouin was previously the Chairman of the Board of the Geensoft Company, acquired in 2010 by Dassault Systèmes, a company which, in the field of development of embedded systems, established itself with the Reqtify product family.
At a glance:
- Dassault Systèmes recognized at an early stage that Systems Engineering is a big challenge for the manufacturing industry, requiring not only new development methods, but also new ways of providing IT support for engineering.
- With its products, the provider intends to support the complete RFLP (Requirements, Functions, Logic, Physics) process from Requirements Engineering through functional analysis and logic definition up to the physical development and testing of the components.
- In 2007 Dassault Systèmes acquired the Swedish company Dynasim AB, one of the market leaders in the area of functional modeling. Its CEO, Hilding Elmqvist, was the developer of the Modelica modeling language and its Dymola graphical interface. By doing so, Dassault Systèmes made an important strategic acquisition in the area of Systems Engineering at an early stage.
- The V6 platform, first presented in January 2008, replace the conventional file management system with integrated database management of all related objects. This in its turn laid the foundation for cross-discipline engineering.
- As the leading IT provider in the automobile industry, Dassault Systèmes participates in strategic research projects. One of the most important is MODELISAR, which particularly aims at an improvement of interdisciplinary cooperation and was initiated by Dassault Systèmes and Daimler.
SIMULIA and V6 – high priority for Systems Engineering at an early stage
Five years ago, the subject of Systems Engineering was mostly handled in a theoretical manner, and outside the aerospace industry, there was virtually no interest. Even among providers of IT engineering applications it was counted as a special case of development, with very little relation to industrial practice if one discounted the actual software system development. Dassault Systèmes realized well in advance of its competitors that Systems Engineering would slowly become the main trend in product development. The software manufacturer therefore made the corresponding investments in this field, the takeover of Dynasim being one of these. When it became part of Dassault Systèmes in 2006, the developer of the Modelica modeling language, Hilding Elmqvist, was CEO, and he continues to head up Dassault Systèmes AB in Lund, Sweden, which was founded in 2010. Modelica is a formal system modeling language that was developed to save and reuse models of systems or system components.
According to Wikipedia “Modelica is an object-oriented, declarative, multi-domain modeling language for component-oriented modeling of complex systems, e.g. systems containing mechanical, electrical, electronic, hydraulic, thermal, control, electric power or process-oriented subcomponents.”
Modelica has been in the public domain since the end of the 90s. Its further development is organized by a nonprofit organization, the Modelica Association. Elmqvist continues to play a leading role here also. The language now includes a comprehensive model library, the Modelica Standards Library (MSL). Modelica is suitable for the description of cross-discipline problems in a broad range of disciplines such as the mechanical, electro-technical and electronics, thermodynamics, hydraulics and pneumatics, control technology and process technology fields.
Before embarking on the programming language, Elmqvist had already developed a graphic development environment called Dymola (Dynamic Modeling Laboratory) that permitted a simulation of complex moving physical models in which graphic symbols represent each individual object. Dymola is today a product of the Dassault Systèmes SIMULIA brand. As well as MATLAB/Simulink von Mathworks, Modelica and Dymola are today the most widely distributed tools for system modeling.
The subject of Systems Engineering also played an important role in the development of the V6 platform. From the beginning, it was linked to the so-called RFLP model, which to a certain extent describes the left-hand descending branch of the "V-Modell". The architecture of the systems is described in the conceptual phase through collecting and describing the requirements. Through analyzing and splitting out the functionality, the next step creates the prerequisites needed to tackle the development of the individual elements and components of the system. The logical interplay of the components then supplies the prerequisite for subsequent testing and validation of the developed components and assemblies.
Source: Dassault Systèmes
In order to support this uniform continuity, for V6 Dassault Systèmes implemented an object-oriented data structure which no longer needs to manage and control the relationships of many individual files, but in which all objects of a complex system are directly linked to one another in the database. This means that conventional data management and the usual exchange of data with customers, particularly between systems of differing origin and data formats, is not necessarily readily compatible.
For Marc Frouin this is a contradiction that is inherent to the subject. “Most of our customers have just started getting to grips with Systems Engineering. Their Development Department is generally organized according to discipline. Work that is based on files was sufficient for this type of development, but the more that interdisciplinary aspects play a role, the more clear it will become that this will also need another kind of object management. We have already taken this step and it will become the norm.”
A cross-sector challenge
Systems Engineering is not a challenge that only affects a particular sector, but the pressure to utilize new methods and tools varies. Dassault Systèmes concerned itself with the requirements of those industries which are positioned as the owners of complex product and system platforms, for the development of which they cooperate with a large number of suppliers and partners. Primarily these are aircraft constructors and automobile industry OEMs. Here the focus is not only the cooperation between different disciplines, but also the synchronization of the hundreds of developers who are making their contribution to the same system.
Source: Dassault Systèmes
Systems Engineering has in the meantime achieved a similar level of importance for many other industries. Marc Frouin names manufacturers of heavy machinery, energy generators, shipbuilding and in general all manufacturers of transport systems as examples. In the user sectors, machine building and mechanical engineering are mostly in the forefront, and it is from this position that the integration of software and electronics is being increasingly tackled.
Source: Dassault Systèmes
However this subject was also particularly important to the high-tech industry from the beginning, for example to the manufacturers of printers or disk drives through to medical technology and specialist suppliers for the aerospace and automotive industries. In these sectors, it tends to be electronics that is the driver, but in the end, the task to be mastered is the same.
Requirements Engineering has two fundamental aspects
Systems are seldom developed completely from scratch. They are mostly subsystems in a complex product and must fit that product’s overall requirements and limitations. Requirements Engineering is, however, in general becoming more important. Although today requirements are still almost everywhere collected and communicated as pure text elements in the form of comprehensive requirements documents and specifications, more and more companies are searching for practical methods by which they can implement true Systems Engineering that collects and follows the requirements placed on a system across its entire lifecycle. From the perspective of Dassault Systèmes, this task consists of two core processes, both supported by special IT tools.
The first process is the capture and the management of requirements, i.e. Requirements Management; the second is the follow-up and analysis of requirements fulfillment in the course of system development, i.e. Requirements Tracing.
In V6, the collection and description of the requirements is the responsibility of the ENOVIA Requirements Central module. On one hand there exists here a deep integration of IBM Rational Doors, which was developed at the time of the exclusive sales partnership between Dassault Systèmes and IBM. On the other, the system is open for an integration of Integrity (PTC/MKS) and other tools that support the management of requirements.
For the follow-up and analysis of requirements, the manufacturer offers the Reqtify product family, which was brought into the product portfolio through the acquisition of Geensoft in 2010. Geensoft successfully supported the development of embedded software with these products. Reqtify links the development, test and validation of components with the associated requirements and permits an analysis of how far the requirements have been fulfilled, or at which point faults or defects have occurred.
The products, which were originally brought to market as standalone, possess a comprehensive list of interfaces that permit the integration of more than 60 engineering tools from a diverse range of manufacturers. The support of numerous standards such as ISO61508, ISO26262, Spice, DO178C, DO254, FDA, GAMP or CMMI is also part of the functionality and of course here also IBM Rational Doors and Integrity are integrated.
Model-based development – the basis for system simulation
One of the major topics in Systems Engineering is how the system to be developed or its individual components is to be modeled. Does the model exist only in a description, or is it an executable model that permits simulation? Is the description alphanumeric or graphical? Are only properties described or behavior as well? Is the model three-dimensional or does it consist of symbols?
In general, there is more than one answer for these questions posed by the Systems Development Department of the company – and the answer is no different for the manufacturers of IT tools. Only Dassault Systèmes currently has such varieties of modeling tools and languages. Their integration is always only one of the solutions that are offered to customers, the other solutions consisting of coupling these tools to those of other manufacturers.
As an example, 3-D models of a component generated using CATIA V6 can be linked with the Dymola/Modelica behavioral models via Dynamic Behavior Modeling (DBM) from CATIA Systems, including the use of all libraries and options on the SIMULIA side.
The Dymola models, however, can also be used standalone. The customer can then use the system’s own capabilities for graphical modeling, or he can link the Dymola models via interfaces to 3-D modeling from other manufacturers or others as CAD models.
Source: Dassault Systèmes
The question of linking of models within system development is in no sense an academic question. Only by linking mechanical models with other electronics and software models can meaningful system simulations be carried out. A sensor checks the position of the tailgate and passes a signal to a controller that accelerates or brakes an electric motor. The functioning of the tailgate can only be simulated to its fullest extent when the 3-D model of the tailgate is linked to the function data from the engine, the electronics and the controller software. In system development, simulation plays a considerably greater role than in pure mechanical product development in order to save development time while simultaneously increasing product quality and avoiding faults.
Because of the enormous importance of the linking of models specific to the discipline, Daimler and Dassault Systèmes initiated and coordinated a research project called MODELISAR in July 2008 in which a total of 29 partner companies from five countries participated. This was carried out within the framework of ITEA2, one of the core projects of the European Eureka research cluster. It was planned to last 3 1/2 years and finished in December 2011. The main goal was the creation of a standard interface to simplify functional simulation involving various software systems, including linking to PLM. It was intended that this should culminate in an open standard for a Functional Mock-up Interface (FMI), and the proposal for such a standard has now been presented (http://www.MODELISAR.com/fmi.html). To simplify the simulation, for example, of vehicle components at an early development stage, a link to the standards Modelica and AUTOSAR is also being aimed for.
FMI permits the inclusion of different already compiled simulation units in a joint framework for combined simulation. This makes a standard available that defines four key capabilities and is the prerequisite for a simulation model. These key capabilities are the exchange of models, an interface for co-simulation, one to Lifecycle Management and one to other applications, for example Hardware-in-the-Loop (HIL).
Even although Systems Engineering is generally becoming a core topic in industrial product development, it is still an important research field in which many tasks remain to be undertaken and problems solved. In addition to MODELISAR, Dassault Systèmes was and still is involved in further European and international research projects. Two examples are:
CRESCENDO was set up in 2009 under the auspices of Airbus and is planned to have a duration of three years. 59 organizations from 13 countries are involved, including leading aircraft constructors, IT and services providers and research and academic institutes. The consortium aims at finding new ways of considerably reducing the costs and time taken by system modeling and simulation in cross-company multidisciplinary system development.
EUROSYSLIB was – just as MODELISAR – an ITEA2 project that ran from the end of 2007 to mid-2010. It aimed at underpinning European leadership in the field of modeling and simulation of embedded systems through further development of Modelica and the available standard libraries. 19 partners from five countries were involved.
A PLM roadmap for Systems Engineering
Source: Dassault Systèmes
For Dassault Systèmes, Systems Engineering is not an additional set of tasks that must be examined from a PLM concept standpoint. The entire V6 platform – i.e. the central PLM tool from Dassault Systèmes – is aligned towards Systems Engineering. In one direction, PLM is understood to be the management of the lifecycle of products from the first idea through to operation or use by customers. This is a direction in which many processes must be linked to one another and integrated. The other direction runs horizontally between the professions or specialist disciplines involved. This comprehensive understanding of PLM also affects the list of priorities that the manufacturers have described for the further development of their own software products in coming years with regard to Systems Engineering:
- Further integration of the products taken onboard through the acquisition of Geensoft – Reqtify, ControlBuild and AUTOSAR Builder – into the V6 environment
- Improvements to functionality in Requirements Engineering and taking compliance into account with regard to simpler usability and simpler access for engineers who are not occupied with these subjects on a daily basis
- Further extension of support for co-simulation to simplify the integration of models that have not been generated using Dassault Systèmes technology via the FMI standard in the V6 environment
- Further integration of modeling and simulation tools from other manufacturers into the V6 Systems Engineering infrastructure
- Continuing the integration of Modelica with 3-D geometry
It will be interesting to see which software workshops and specialist suppliers in this environment will be the next goals of strategic acquisition by Dassault Systèmes. The manufacturer will, of course, have its eyes in this respect just as wide open as the competition has. But where its glance is directed remains – at least for the moment – a secret.