Powering the Future: How Polarion Drove the Hydrogen-Electric Truck Revolution
Pioneering E-Mobility: RWTH Aachen’s Vision for Heavy-Duty Trucks
The Chair of Production Engineering of E‑Mobility Components (PEM) at RWTH Aachen University conducts application‑oriented research across the e‑mobility value chain—battery systems, fuel cells, drivetrains, testing, recycling and vehicle integration—bridging scientific methods with industrial implementation. PEM excels at linking product development, production system design and industrialization (demonstrated at StreetScooter), supporting electrified commercial‑vehicle R&D. For example, the SeLv project developed a modular hydrogen–battery electric drivetrain for heavy‑duty trucks, integrated into a donor vehicle and designed close to series production for conversions or OEM deployment.
Navigating Complexity: The Systems Engineering Approach
Development faced high complexity from diverse stakeholder, regulatory and market demands (e.g., ISO 26262, ISO 9001, D‑FMEA, ISO 21434). The SeLv project used a holistic systems engineering approach to build an interdisciplinary development system across all lifecycle phases, with horizontal integration across the phases of definition, concept, development, validation and series preparation as well as vertical integration across mechanics, hardware, software and quality. The process centered on a shared engineering backbone.
Polarion: The Central Anchor of the Engineering Backbone
At the core of the engineering backbone was Polarion ALM, the central requirements‑management system. Requirements from all participating disciplines were captured, consolidated and managed in a single shared environment across the lifecycle.
Polarion went beyond documentation. It functioned as an active control instrument for development. Requirements, functions, functional safety, cybersecurity, project management, test planning and test documentation were handled consistently and maintained with full traceability.
Together with Siemens Teamcenter as the PLM system, Polarion formed an integrated toolchain linking requirements, models, bills of material, tests, quality artifacts and safety artifacts.
From Requirements to Specifications: Building the Product Blueprint
PEM started the development process by collecting and structuring requirements in Polarion. Because road approval of the drivetrain was a key objective, analysis of homologation requirements played a central role: for each relevant legal act a dedicated Polarion document captured the project‑specific legal requirements applicable to the vehicle and drivetrain.
Requirements from other stakeholders were analyzed and added in parallel. All requirements were then consolidated and mapped to the vehicle, system and component structures, producing an end‑to‑end product specification spanning vehicle, system, component and software levels.
Homologation requirements relevant to the drivetrain and its integration into the complete vehicle were recorded in Polarion as legal requirements and integrated into the vehicle structure, allowing legal constraints to flow directly into vehicle development.
For example, a gradeability requirement defined at the complete‑vehicle level was propagated through the energy‑management concept to derive system requirements, including electrical continuous power, mechanical continuous power, the battery system, the fuel‑cell system and other subsystems.
Accordingly, the product specification functioned as a living development model rather than a static document, systematically translating requirements into concepts, detailed concepts and concrete specifications.
Translating Vision into Reality: Concept & Detailed Design
During the concept phase, multiple complete-vehicle concepts were analyzed, documented, and evaluated in parallel against the overall vehicle requirements specification. The resulting vehicle concept comprised several key units: battery units; fuel‑cell and auxiliary units; the drive unit with power distribution; fuel‑cell cooling; and the tank unit.
From this overall concept, PEM developed detailed concepts and translated them into specifications for systems, components, and software building blocks. Polarion supported and documented the entire process, ensuring that decisions, requirements, and derived specifications remained fully traceable down to the BOM structure in Teamcenter.
Managing Implementation: Bridging Requirements and Realization
During the implementation phase, component requirements were realized within the respective engineering disciplines, while Polarion continued to govern and document their implementation. Mechanical and electronic requirements were linked to their implementations via Teamcenter. Software requirements, by contrast, were linked directly from Polarion to their implementations in MATLAB Simulink.
This arrangement improved traceability from requirement to software implementation and provided a sound basis for continuous validation.
By linking Polarion requirements with Simulink models, a surrogate representation in Polarion displayed essential information from Simulink, making it straightforward to see how individual requirements were implemented in the software model.
Ensuring Quality: Verification, Validation, and Continuous Optimization
Verification and validation activities were managed and documented in Polarion. Test plans were linked to the requirements they verified, test cases were derived at multiple system levels, and test runs — including results — were recorded directly in the system.
Validation took place at software, component, and complete-vehicle levels. The project developed, built and operated three successive vehicles:
- SeLv 1 for early functional and integration validation,
- SeLv 2 as a prototype of the final configuration, and
- SeLv 3 as a pre‑series stage.
By managing requirements and test specifications in a single tool, the team greatly simplified evidence of requirement fulfillment. All stages of the V‑model’s right-hand side could be demonstrated in a structured, traceable way — from verification of individual software modules to validation of the complete vehicle. Test results continuously fed back into system optimization and supported preparation for near‑series processes and production.
The Power of Traceability: Reducing Risk, Boosting Efficiency
Through the consistent linking of requirements, concepts, software models, test cases, and validation results, the SeLv project established robust traceability across disciplines and development phases.
Polarion became the central anchor point of an engineering approach that connected homologation, systems engineering, software implementation, and physical validation. For complex electrified commercial vehicles in particular, the project demonstrates how an integrated engineering backbone can help reduce development risks, increase requirements transparency, and make the path from concept to validated vehicle more efficient.
About the Experts:
This case study draws heavily on the experience of Michael Demming, who worked for several years in requirements management and safety at StreetScooter before joining the Chair of Production Engineering of E-Mobility Components (PEM) at RWTH Aachen University in 2021. At PEM, he has led and contributed to various vehicle development projects, including SeLv, and served as group lead for full-vehicle development. His work builds on the application-oriented vehicle development approach shaped by Prof. Achim Kampker, co-founder of StreetScooter and head of PEM at RWTH Aachen University, where projects such as SeLv have been implemented with a strong focus on rapidly translating innovative ideas into concrete requirements and real-world vehicle applications.
