The introduction of Industry 4.0 is currently mainly taking place in large companies. In order to introduce the concepts and technologies of Industry 4.0 into small and medium-sized enterprises as well, however, there is a need for organizational tools, which show which Industry 4.0 concepts are best suited to the respective size of enterprise. At present, there is no scientifically founded knowledge on this subject. Therefore, based on a company survey and an expert survey, this paper examines and discusses the suitability of industry 4.0 concepts in different company sizes. The aim is to find out which Industry 4.0 concepts are considered promising by users (enterprises) and experts. On this basis, a final list of suitable Industry 4.0 concepts per company size will be provided.