A static matrix model in a viscoelastic body is generated for each environmental temperature condition. A generalized Maxwell model is generated for each environmental temperature condition using a matrix of the static matrix model. A spring coefficient and a damper viscosity coefficient of a material test piece is identified as a function of a strain rate norm based on a measurement result of the material test piece using a temperature-time conversion rule. An average strain rate of a part is identified as a function of a displacement rate vector. A dynamic spring coefficient and a damper viscosity coefficient of the part are identified as a function of a component of the displacement rate vector. A generalized Maxwell model for analysis is generated by applying the dynamic spring coefficient and the damper viscosity coefficient identified as the function of the component of the displacement rate vector to the generalized Maxwell model.