Technical parts with high quality requirements are manufactured by injection molding. Within the framework of this thesis the expert system EXINMOLD (= Expert System Injection Molding) was developed. The software EXINMOLD can be used for the development of tools for injection molded parts and assists the technical designer at all steps of the tool development. It provides information and knowledge about planning, construction and production of injection molded parts and tools for the tool designer in a fast and structured way. For the development of EXINMOLD continuous investigations of more than 35 injection molded parts and tools were performed. All parts and tools were computed with the simulation program Moldflow Plastics Insight. The computation results were verified experimentally for all molding process phases. To evaluate the calculated shrinkage and warpage of the parts an optical 3D-scanner with special evaluation software was used. The experiences from these investigations are accumulated in EXINMOLD. Beyond that substantial literature- and expert-knowledge is saved. By processing and documentation of tool projects with EXINMOLD this knowledge rises continuously. This approach represents the integration and reuse of information from projects already completed, in the context of a consistent knowledge management.