A design navigation system was created to help designers by combining design knowledge and tools in a step-by-step process. This system guides designers through each design step using different sources of information and know-how. It breaks down the design process into clear steps, shows it in a work breakdown structure, and allows designers to search for necessary knowledge as they go. By using this system, designers can shorten design time and improve the reliability of their designs. The system was tested on a piston design process and was found to be effective in achieving these goals.