Manufacturers begin to give more and more customizing offerings and services of their products in order to create the values that really fits customers' needs and wants rather than to supply materialized products directly. Systematic design approaches and modularized computer-aided design systems are the key to reduce the design complexity and would lead to successfully converge divergent thinking and creativity to the specifically defined problems. Therefore, this research aims to propose a creative design system framework with an integrated method of customizing product/service systems (PSSs) for the solution modularization. A systematic design model consists of three phases: 1) identify problems and initial design (IPID); 2) design trimming and resolution generation (DTRG); 3) interaction mapping and design evaluation (IMDE). In phase I, we can understand customer requirements through interviewing by knowledge elicitation methods and root cause analysis. In phase II, we can generate more possible service components related to a specific product characteristic by innovative principles of the theory of inventive problem-solving. In phase III, we can assign the interactions between service components and customer needs to create PSS solution modules. A computer-aided design system environment, called SCO Explorer, is developed based on the above design phases and theoretic concepts to represent a solution design environment with the design requirements and to determine the input parameters of each phase. As the result shows that we verified the usefulness of the design method and tool by applying to existing PSSs by an electronic manufacturer to carry out a PSS solution.