Model-based Systems Engineering

The time is ideal to get to grips with systems engineering, or better still: to get together. SAP recently launched Intelligent Product Design (IPD), a cloud solution that enables deep integration of systems engineering scenarios into PLM and SAP infrastructure, industrializing model-based systems engineering (MBSE).

SAP IPD highlights include: model-based requirements management and systems engineering; collaboration capabilities for workflow-based collaboration; test management for verification and validation; and requirements capture from product operations.

The great advantage of IPD is that interfaces to the SAP world no longer have to be developed and CAD-agnostic work can be done. Previous initial attempts to move in this direction with freeware products were often abruptly ended by the company's own IT department. With IPD it is possible to move the starting point of PLM forward by means of comprehensive requirements modeling and not to start the link to SAP objects with SAP Engineering Control Center (ECTR).

The Enterprise Architect Designer for IPD (tool for model-based system development) works with SysML. The description language SysML has been standardized for a long time, but it has not yet been possible to speak of broad acceptance. SysML significantly improves cross-discipline communication because systems can be described holistically through models.

E-3 interlocutor Jakob Röhrenbach, Account Executive Digital Supply Chain SAP at Cenit, provides assistance: "In systems engineering, the challenge is to make the added values hidden in the system models transparent in the processes."

The methods of systems engineering have been known for a long time and at least fragments of knowledge are available in almost every company, emphasizes Röhrenbach; however, the impetus from outside is necessary when it comes to establishing systems engineering sustainably and comprehensively. And this is precisely the role in which the company sees itself:

"As an SAP partner, Cenit was focused from the very beginning on the early phases of the product lifecycle: on the creation of 2D and 3D CAD models and their transfer to further downstream processes, for example in the area of manufacturing. We have also accompanied our customers in the introduction of 3D master concepts. This has resulted in enormous competence in the form of a consulting team and expertise in mapping this in a supply chain model."says Röhrenbach.

Digital Supply Chain

SAP has several E2E approaches in its quiver, including one for the digital supply chain. According to the Walldorf-based company, this value chain is divided into the phases Design, Plan, Build, Deliver, and Operate (D2O), whereby the domain of MBSE focuses on design in the D2O cycle, but can also provide value contributions for the other phases.

"Until now, the D2O chain has often spanned data and departmental silos with system and organizational breaks. MBSE can offer an approach here, both methodically and process-technically, not only to be able to fall back on a cross-domain product model in the engineering disciplines, but also to hold aspects of the entire PLM cycle centrally and neutrally.", says the second E-3 interlocutor, Christian Markus, an expert in MBSE and SAP IPD at Cenit subsidiary Coristo, emphasizing:

"What's special about the new SAP IPD solution is its deep integration and thus access to SAP business objects."

What distinguishes MBSE's claim to consistency in communicating with the various stakeholders from that of the 3D master?

"Basically, there are two parallel approaches that complement each other. The spheres of action are separated from each other, because the system model includes all development-relevant content and relationships, while geometry-based information, such as for manufacturing, is carried along in the 3D master. In particular, requirements and their relationship to the changes are mapped without contradictions in the system model via the system diagram."explains Röhrenbach.

The system model includes so-called satisfied relationships for requirements modeling and verified relationships for test scenarios. Röhrenbach points out, however, that systems engineering should not be understood purely as requirements engineering, i.e., as requirements modeling, although this is of course a very important point. What both approaches, MBSE and 3D Master, have in common is that they both pay attention to the digital twin of a serialized (product) instance.

"The MBSE model is very valuable when a virtual prototype is to be generated, because all structured cause-effect relationships are available virtually on demand and it is transparent at all times what is being tested."adds Christian Markus - MBSE models are at the beginning of a digital thread that can lead to the digital twin.

Digital twin

Modeling in the sense of systems engineering is definitely in sight for most companies. They are created or refined on a daily basis using authoring tools such as MCAD or ECAD. However, there are still many gray areas in the area of requirements management, because people like to work with MS Excel.

"The important thing at the beginning is to approach systems engineering with a clear will. Taking stock of the current situation is necessary, for example to realize how much of this is already anchored in the company: Who in the company is interested in this? Who is informed? And who is enthusiastic about MBSE?"Markus asks in the role of change agent.

Now the time is ripe for an example. The well-known systems thinker Russell Ackoff has dealt intensively with object contexts and agile limits of what is possible:

"Problems don't need to be solved, they need to be resolved" is one of his strong phrases that can also be used as inspiration for product development. Together with SAP, Cenit has designed the eScooter training plan.

"The decision to model an eScooter as a system was motivated by the idea of extending a largely mechanical motor scooter into a lived IoT scenario with electric scooters in free-floating sharing systems"says Markus.

The training plan focuses on recuperative braking on electric scooters. Is this worthwhile for such a lightweight vehicle, or isn't a sailing function better after all? Feedback from the field (via service app) revealed that customers wanted recuperation especially when driving downhill, as they are afraid to run the brakes hot.

So far, this type of recovery has only been discussed from an energy management perspective, but not from a customer experience perspective. In addition, the service app announced that the installed disc brakes would not meet the requirements over the entire operating time of the scooter.

"In an intuitive way, you move away from a pipe and towards platform thinking, where the target group actively helps to shape the product design. This is where the system idea reveals itself, namely that the product is not just in the shop window, but in a context of use and environment.", says Röhrenbach and Markus adds:

"The approach behind this is to develop much closer to the market than before. MBSE based on SAP IPD is exactly the instrument to practice this agile development, because via IPD it is possible to open up a much larger number of feedback channels for a product."

Most engineers think intuitively in terms of models, even though they may use different terminology for them.