"Crafting Business Models and Value Propositions with Serious Play" is a professional book aimed at experienced facilitators, describing the development, prototyping, and evaluation of an innovative LEGO Serious Play tool. This toolkit helps facilitators guide representatives from organizations, whether in non-profit associations or Fortune 500 companies, in the (re)definition of their business models. By fostering creative self-confidence and creating a shared understanding of business models and value propositions, the book aims to contribute both scientifically and practically. The author, Reinhard Ematinger, explores significant research gaps and formulates key research questions to determine whether a shared understanding of business models and customer value propositions can be enhanced through a Serious Play approach. The detailed methodology and findings of this study provide valuable insights for both practitioners and scholars alike.