This chapter explores systems thinking and business models as foundations for sustainable product development. A system is defined by boundaries, inputs, and outputs of energy, material, and information, progressing from abstract to concrete models. Systems engineering provides an interdisciplinary framework to manage complexity, linking societal systems such as mobility, energy, health, and education to sustainability goals. The legal framework acts as a central driver: instruments like the Renewable Energy Act and EU emissions trading influence market profitability, investment, and innovation through incentives and penalties. Scenario techniques are introduced as strategic tools to anticipate future developments by integrating political, economic, technological, ecological, and social factors into plausible futures. The Eurac South Tyrol study illustrates four scenario pathways emphasizing robust strategies under uncertainty. Corporate strategy and portfolio management align long-term objectives with resource allocation using technology and market-technology portfolios, exemplified by the evolution of lighting technologies. Finally, new business models are discussed, highlighting rental, sharing, and product-service systems. Extending the Business Model Canvas with ecological and social dimensions enables companies to shift from ownership to service provision, reduce material throughput, and foster circular economy approaches. The chapter thus positions system-oriented business models as essential for integrating sustainability in technology and corporate strategy.