Abstract
Actual product designs aim to fulfill all product requirements of market needs and wants, which are technical or non-technical, logical or illogical, objective or subjective, and quantitative or qualitative. The actual product designs are objective-aiming designs and can be supposed to be multi-objective satisfactory designs with heterogeneous objective functions and dimensional design variables. To realize computer-aided product designs which can obtain rational and satisfactory solutions, we classify the objective functions and contrive methods to deal with non-theoretical, non-technical, subjective, or illogical objective functions as well. This paper shows all of our methods, including an expression of heterogeneous objective functions which consists of objective and evaluated values, a satisfactory design method by simultaneous equations which searches solutions sequentially, identification methods of non-theoretical or non-technical objective functions and sensitivity coefficients for the simultaneous equations, a decision-making method of promising solutions to fulfill product requirements, and also numerical applications of these methods to actual product designs.