This study addresses how constraint-based thinking can support the development of frugal innovation and enhance understanding of its benefits ex-ante. Through five case studies of SMEs and research groups across four continents developing frugal products in the medical devices sector, we demonstrate that the constraint-based thinking framework emphasizes understanding resource scarcity and differentiating constraints to produce effective frugal features or functions. The research highlights the importance of early identification of business constraints that evolve during the new product development process. Moreover, it suggests that constraints should be viewed as opportunities to attract external partners and collaborate with academics and users. Consequently, we propose two steps focused on open innovation and a repetitive step for evolving the constraint-based thinking framework. This study provides a more pronounced overview of existing knowledge on constraint-based thinking in the context of frugal innovation. Practitioners benefit from an algorithmic and iterative concept applicable to the earliest stages of new product development.
