Using the valve train as the subject material for this research, a method was created for rapidly realizing optimization through a high-level reconciliation of conflicting relationships between numerous functions and systems that had formerly presented issues in the time required for verification. Multi-objective design exploration, which clarifies relationships among multiple requirement items necessary for a design and determines their design range, was used for this research. As this approach significantly reduced the period of time for determining specifications compared to conventional development, it is reported herein.