System of Systems Engineering-Based Design of Business Models for the Circular Economy

In terms of environmentally, economically, and socially sustainable development, meeting current needs must not restrict those of future generations. Currently, humanity is exceeding several planetary boundaries, which serve as a critical reference point for assessing this condition. The circular economy is considered a pathway to resource conservation and emissions reduction, enabling economic activities to remain within ecological planetary boundaries. However, the implementation of the circular economy is impeded by various barriers. A central challenge for companies is designing business models and, due to the growing interdependence of material and financial flows, aligning them within the circular value creation architecture. To avoid problem shifting and rebound effects, a systemic perspective beyond the focal company is required. However, this is not sufficiently addressed by existing frameworks and tools for business model design. This dissertation develops and validates a multi-level, multi-perspective engineering framework for the design and alignment of interdependent business models within a circular value creation architecture. Building on conventional business models, the normative frame of sustainability-oriented innovation, and systems of systems engineering, requirements for the engineering framework and the tool are derived. The engineering framework is specified in terms of processes at the micro- (company) and meso-levels (circular value creation architecture). An interface design framework is developed to ensure alignment and to connect both levels. For operationalization, a pattern-based approach is proposed that integrates existing types of business model patterns at the micro- and meso-levels, covering both value creation and capture. Using design science research, a card-based tool is implemented to enable the framework application and to support individual companies or groups of companies in designing business models and circular value creation architectures. The relevance and applicability are validated through demonstration workshops across representatives from three industries (photovoltaic, electric vehicle batteries, and furniture). This dissertation bridges the gap between abstract business model development and the systemic, multi-actor realities of the circular economy. The conceptualization of interdependent stakeholders guided by their business models, grounded in the systems of systems approach, expands the understanding of business models as dynamic, interdependent systems. It offers a structured methodology for designing and analyzing business models beyond the focal company. By developing an engineering framework and practice-oriented tool, this dissertation contributes to closing the design-implementation gap of the circular economy.