In the development of complex mechatronics products, It is requested to pursue its add-value, are increasingly being required to develop a complex and delicate features. But the failures of high-functional feature are found in the prototype-stage, and experts try to solution with "Suriawase", it has led to an increase in rework effort. The authors predict that there are insufficient validation of behavior on design phase, so failure has become apparent in the prototype stage. In order to design high-quality behavior, the authors propose a design approach that integrates object-oriented analysis and parameters constraints. In this approach, the authors adopt the phase diagram to analyze the states and make clear the points that should be verified.