Two types of mistakes can often be observed in strategy design processes. The first is executives believing that they know their customers better than customers know themselves. This leads to offerings being developed that nobody wants or nobody is willing to pay for. On the opposite end of the scale, the second big mistake observed is that decision-makers are only willing to decide if they are 100% convinced that change will be successful. A key feature of design thinking for strategy to address these mistakes is experiment-based validation with real customers. During designing the detailed business model, choices are made based on sound assumptions. Assumptions must be validated. To do so validation experiments are designed. They primarily focus is on trying to invalidate the assumptions made rather than confirm the already known, in line with the credo of fail fast, to succeed faster. The outcome of the validation phase is one or more business model prototypes that are desirable, feasible, and economically viable.