Digital development methods are shortening Time-to-Market for data cables in the automotive industry

Modern vehicles require highly complex on-board networks with data cables stretching for miles. These cables must be extremely reliable and powerful, especially for safety-critical applications in autonomous vehicles. At the same time, mega trends such as the software-defined vehicle are demanding ever faster development cycles and innovative solutions. Time-to-Market, i.e. the time from the idea to market launch, is becoming a significant competitive factor. Technological and economic advantages are up for grabs for those who manage to get new systems to market quickly. No one has time to wait for lengthy development loops anymore. Digital development methods should help to achieve series readiness more quickly. But what are these methods exactly?

High technical and procedural complexity

Particularly during the gradual introduction of autonomous vehicles, data cables must perform better than ever as they are the “nervous system” of modern vehicles. They have to transmit high data rates and must be resistant to EMC, temperatures and bending – while saving space and ideally, reducing costs.  At the same time, classic sequential development processes are making rapid implementation more difficult: long rounds of approval, fragmented combinations of tools, complex interfaces between specialist departments, and revalidation of every design change take up valuable time. All too often, construction, simulation, validation and production processes are carried out in separate systems – without one consistent pool of data. Information is transferred manually, reprocessed or converted into incompatible formats. In the area of on-board development, it is estimated that engineers spend up to 80% of their working hours making and coordinating changes – this is a huge time factor! These bottlenecks make one thing clear: in order to shorten Time-to-Market, new approaches need to be taken to master technical challenges and accelerate the development process.

Simulation: validate at an early stage and save time

Early simulation can shorten development cycles significantly. Highly developed simulation software makes it possible to virtually test EMC properties, signal behavior and the selection of materials at an early stage. This means that undesirable developments can be avoided, and the number of physical prototypes can be reduced. A concrete example of this is the BordNetzSim3D project promoted by the BMWK (German Federal Ministry for Economic Affairs and Climate Protection). This is the first time that an entirely digitalized platform has been implemented, enabling companies to develop onboard networks using simulation – from the design phase through to series production. This digital approach shortens Time-to-Market by already securing design decisions during the design phase.

Digital twin: virtual images as a development accelerator

While simulations often uncover individual aspects or test situations, the digital twin goes one step further. The digital twin maps a replica of a physical product – including geometry, electrical properties and external influences – on a 3D data model. This enables cable systems to be simulated and optimized in real time. Developers can simulate operating behavior in the vehicle even before the actual prototypes are created. This means, for example, that mechanical stress, thermal aging or electrical interference can be acted out on the digital model. All process steps – all the way through to production – can be seamlessly interlinked and arranged on one and the same digital basis. If a problem is identified (e.g. overheating in a specific area), the 3D construction can be adjusted and tested virtually again – and this all within a few days rather than a few weeks. In practice, digital twins are already improving collaboration beyond teams and national borders in the automotive industry. Changes are reported centrally and made visible for everyone. This “single source of truth” principle prevents inconsistencies and enables teams to work in parallel. So, construction, simulation and production planning can be carried out simultaneously and no time is lost waiting for one another. One common, up-to-date pool of information is used by different teams who keep their subsystems synchronized. Design changes are tested and synchronized directly on the digital model, saving time, improving quality and enabling parallel development.

Rapid prototyping: faster samples and feedback loops

Despite all these simulations, an actual prototype still remains essential in many cases – whether that be for haptic tests, test fitting on the vehicle or for customer presentations. Rapid prototyping refers to methods used to produce such sample parts particularly quickly. Especially 3D printing (additive manufacturing) has introduced a paradigm shift. 3D printing creates a three-dimensional object from a CAD model within a few hours. Components can be rapidly created, adjusted and reproduced. Additive manufacturing is already able to drastically accelerate development times. This often leaves developers with more time to sound out different design options. So, rapid prototyping not only helps to design more flexible and more customer-focused projects, but also to promote creativity: more cycles in shorter time means that various ideas can be tried out and optimized before the design is put into series production.

Delta testing: selective testing rather than validating everything over and over again

In the past, virtually every change meant that an extensive overall validation had to be carried out. Numerous tests had to be repeated in order to ensure that all specifications continued to be met. That took a lot of time. This is precisely where the delta testing approach comes into play. Instead of running through the entire test program, if a change is made, designers can focus on the areas in question and go back to the delta from the previous stage. This means that only the components actually affected by the change are tested – for example, in the case of changes in materials or minor layout adjustments. Transparent documentation of changes and digital traceability are essential here. Simulations and digital twins help narrow down the consequences and estimate the risks correctly. All in all, in change management, delta testing enables adjustments to be handled swiftly. Updates and improvements can be integrated more quickly without having to constantly disrupt the release schedule.

“Concurrent engineering” – parallel development

A central lever for shortening development times is the change from sequential to parallel development. In the classic “waterfall model”, each process step (e.g. housing design) has to wait for the previous step to be completed (e.g. completion of the circuit diagram) before the next step can begin. This model leads to long waiting times and slows down the entire project unnecessarily. Concurrent engineering breaks this pattern: several development tasks can be undertaken simultaneously in a closely coordinated manner. For example, designers work on mechanically integrating the data cables into the vehicle while electricians are still optimizing the circuit diagram – both teams continuously coordinate with each other and repeatedly adapt their partial results. Integrated data models and a high level of information exchange are essential here. Everyone works simultaneously on the product – supported by shared data models, for example, in PLM (Product Lifecycle Management) systems. In the process, the digital twin serves as a central source of information. Problems are detected and remedied at an early stage. By using parallel development, you can save time and improve the quality of results. Problems or inconsistencies between trades (e.g. installation space is too small for a sheathed cable) can be detected earlier, as the teams work on the entire networked system at the same time. Adaptations are no longer made at the very end in complex modification loops, but continuously throughout the process. Everyone works towards an optimally harmonized design.

New work: agile methods and distributed teams

The influence of modern work methods on development time should not be underestimated. Technical tools alone are not enough – the way in which people work together has a decisive influence on the speed and quality of development projects. Flexible thinking is increasingly finding its way into vehicle development, traditionally characterized by long-term cycles. Methods from the software world, such as Scrum or Kanban, are being adapted to hardware projects to make it possible to react more quickly to changes. This means, for example, organizing development in short sprints, assessing prototypes (including digitally) at an early stage and regularly, and continuously collecting feedback. Cross-functional teams made up of developers, product planners and quality specialists bring together the necessary extensive know-how to master complex tasks quickly. Digital tools and digital twins facilitate cooperation and remote collaboration, enabling projects to be worked on across different locations in real time.

The introduction of such work methods may well be associated with a change in culture, however it is paying off with faster and better results.

Globally coordinated product development teams with unified CAD systems at MD ELEKTRONIK

MD has long since recognized the trend and advantages of digital development methods and successfully implemented many of these building blocks in various development projects. One example of this is the parallel simulation assessment of 3D models during product design. Through FEM simulation, the mechanical, dynamic and thermal parameters of the future component are verified at an early stage, and high-frequency, electrical simulation evaluates the parameters for high-performance data transmission. In addition, an extensive material database has been developed containing the basic properties of polymers and metals with design-dependent factors, e.g. temperature development, attenuation and dielectric conductivity for time-saving installation.

Our Rapid Prototyping Centre provides interdisciplinary development project teams with prototypes based on digital twins using a variety of printing technologies. This enables tests to be carried out at the customer’s premises and with development partners during the design phase. Complex system architectures can be tried out from several suppliers and the interaction of components can be examined, and all this at an early stage in a prototype vehicle, technology demonstrator or pretest vehicle under realistic conditions.

Thanks to MD’s global presence, customer project meetings can still take place while parallel design loops for housings, contacts and functional parts ensure a fast development cycle. Based on the central 3D model, production processes and tools are developed as soon as the design reaches a certain stage of maturity. Once again here, the digital twin is the basis for the injection molding simulation which identifies and minimizes the influences on performance of the subsequent production tool on the component.