This research is in the domain of service science and proposes a method for designing service systems. We consider three levels of design – individual, organizational, and implementation. The proposed design method links these three levels by explicit input, output, and feedback between them. We use a design science research approach to design the method. This dissertation solves a practical question – how to design businesses that fit market needs, and has a theoretical contribution as it advances service science by combining theories from three domains: cognition (opportunity recognition), business modeling, and software engineering. We use systems thinking principles to federate the above theories. We gather data and validate our concepts in three contexts – a university course, startups, and established companies. We develop the necessary constructs and models, and conceptualize the final method in three iterations.