Process trimming (also can be called as trimming for process) helps to trim and eliminate process operations by redistributing their functions among other operations. It offers one way to eliminate key disadvantages in product and manufacturing process that other methods do not see. However, few methods have been disclosed in a structured way for process trimming effectively. Therefore, this article proposes an integrated process focused on technological process and product innovation to solve the key problems with process trimming-based TRIZ (theory of inventive problem-solving) approach. This method helps to identify and inventively solve the key problems and maximize use resource of system and supersystem. First, process trimming candidates are identified based on component function model, component trimming rules, process function model analysis, component–process interaction matrix, and root cause analysis. Then, three types of process trimming strategies are presented. Algorithm of process trimming is developed to identify key problems in technological process. TRIZ problem-solving tools are used to solve these key problems. Finally, a case study of refrigerator door foam innovative design and manufacturing process is investigated to test the efficiency of the approach. The innovative solution significantly decreases manufacturing defects and service cost.