From the literature it is known that standards may positively impact innovation, but how? This paper focuses on the role of standards in the creativity part of the innovation process. Standards put constraints, and this might hinder creativity. Applying the theory of constraints, it is argued that the opposite can be the case: standards may stimulate creativity. Standards may set input constraints, process constraints or output constraints, and may influence innovation via different routes: the motivational route, the cognitive route and the social route. Standards can be both internal standards, defined by the company itself, and external standards. These may apply both to products and to services. Current literature tends to focus on output constraints only: by providing requirements for products or services, standards steer the creativity in the preferred direction and may trigger the development of solutions that meet the requirements. But standards may provide input and process constraints as well. In the product case this can be understood using the concepts of component commonality, platforms, modularity and postponement. For services, standards may apply to, for instance, service delivery, service results, precautions, and ethical codes for employees. But also for services modularity may apply: services can be assembled in service packages.