Driven by the increasing need for sustainable system efficiency, electric vehicles are increasingly using recuperation for braking. The vehicle brakes up to a certain g-value via the electric engine, otherwise via a mechanical brake. If this value is increased through an update, the system behaviour of the mechanical brake changes, necessitating additional modifications or changes to the hardware, also known as upgrades. However, a model-theoretical description of updates and upgrades is lacking in the literature. Therefore, this thesis aims to answer the following research question: How can updates and upgrades of mechatronic systems in CPS be described using the model of SGE – system generation engineering? The answer to the research question is divided into three steps, each with a distinct methodological approach. The results are built on the basis of a previously published systematic literature analysis. In the first step, a common understanding was established to enable the description of updates and upgrades through the model of SGE. The example of recuperation was used in the case study, where the recuperation limit is raised from 0.25g to 0.3g. Based on the case study and the systematic literature review, differences between updates and upgrades were discussed, and several definition proposals for upgrades were created in the context of the model of SGE through an explorative literature review. The definitions are based on the principle of generic and specific, so that a general part of the definition can be distinguished by specific characteristics from other definitions such as the update definitions according to ISO/IEC/IEEE 14764:2022. The first result is a model-theoretical description of updates and upgrades based on the understanding of the model of SGE. In the context of SGE, updates and upgrades involve a large amount of takeover of the generation on the market SGn-1 into the reference system Rn of the generation under development SGn. As a result, there is a high concordance of sub-systems in the development of SGn, which means that updates and upgrades determine the new development share. Based on this understanding, upgrades are defined in the context of of SGE as follows: An upgrade is a modification of a mechatronic system that adapts the usability and/or the performance of the product to uncertain/changing supplier, customer and user needs and boundary conditions by improving and/or extending functions of the system through an adaptively designed product architecture by adding or changing - in the sense of the variation types of the model of SGE - subsystems within the use phase. These upgrades are provided to customers and users through a suitable business model. However, these results are limited in their generalisability, as the basis was discussed in one specific example, the braking system. The foundation needs to be explored in other settings where updates and upgrades occur to confirm transferability and generalisation. In addition, the consistency of the upgrade definition in the context of the SGE model with other prevailing definitions needs to be investigated. The definition of updates according to ISO/IEC/IEEE 14764:2022 must also be considered. In summary, a common understanding of updates and upgrades can be established through the previously published systematic literature review based on the SGE model. Thus, the SGE model provides a basis for describing and modelling updates and upgrades in the product engineering process. Additionally, the definition shows that upgrades refer to the modification of mechatronic systems, and that these changes in the system can be described using the three operators, the variation types in the model of SGE, for upgrades. The integration of business models into the definition is also consistent with the understanding of innovation in the literature.
Prof. Dr.-Ing. Albert Albers, Head of Institute, IPEK - Institute of Product Engineering at Karlsruhe Institute for Technology (KIT)