In this article, a mobile, internet-based service tool for the support of technical customer service processes is described. The tool uses a fuzzy component structuring repair information formatted for multimedia use and makes this information available to customer service technicians through the process-oriented use of mobile end devices. Through the use of mobile technologies in connection with the knowledge of experienced customer service technicians with respect to inspection, maintenance and servicing work and through the processing of this knowledge in accordance with fuzzy rules, the efficiency of the service process can be increased. The potential use of this system is exemplified by means of a real-life application from the heating, air conditioning and sanitary engineering (HAS) branch.