A Modular Design Strategy Catalogue for the Product Portfolio Transition of Automotive SME Suppliers to Electric Mobility

Automotive suppliers below the tier-one level face the replacement of combustion-specific components by battery electric ones and must change their product portfolio through concrete design decisions on individual parts. Design engineering offers an extensive method inventory for such situations, but it was developed for organisations that own their development process and staff specialist functions, and guidance on which methods such a supplier should apply, at which point, and in which order is absent. This paper derives 40 problems facing these firms from the scientific literature, consultancy analyses, and publicly available stakeholder statements and compiles 48 design engineering methods characterised by development phase, role, input, output, operation, and object level. Four rules link the two, identifying admissible methods, their input requirements, and possible prerequisite sequences for a specified supplier problem and firm profile. The resulting Modular Design Strategy Catalogue is illustrated using two constructed supplier profiles and critically assessed using the Validation Square; its effectiveness in industrial practice is not evaluated. Within the compiled inventory, enabling methods outnumber transforming methods, and support for conformity demonstration remains limited. The framework is extensible: a method characterised along the same dimensions enters every entry for which the rules admit it.