Method of determining optimum product design parameters and system therefor

A computerized method for manufacturing a product having optimum design parameters, which comprises the steps of:

• 1) inputting evaluation values obtained by evaluating a plurality of trial products each having a combination of one of several levels given for each of a plurality (n) of design parameters (P1, P2 . . . Pn) regarding a plurality (m) of evaluation items (D1, D2 . . . Dm);
• 2) for one design parameter (p1), obtaining a system range (Rs) for each level from an average of evaluation values of one evaluation item (D1) for each level (d.sub.ave) and a standard deviation (.sigma.) in accordance with the equation of Rs=d.sub.ave .+-.a .sigma. where a is a positive constant of 1.0 or more;
• 3) obtaining an amount of information (I1) for each level from the system range (Rs) and a predetermined design range (Rd) in accordance with the equation of I1=1n(Rs/Rc) where Rs represents the system range and Rc represents an overlapping range of the system range (Rs) and the design range;
• 4) similarly obtaining amounts of information (I2 to Im) for each level of the design parameter (P1) for the other evaluation items (D2, D3 . . . Dm);
• 5) adding the amounts of information (I1 to Im) of the evaluation items (D1 to Dm) to afford a total amount of information for each level;
• 6) depicting a characteristic curve of the total amount of information for the design parameter (P1);
• 7) determining a value of the design parameter giving the smallest total amount of information as an optimum value of the design parameter (P1) based on the characteristic curve;
• 8) performing the steps 2) to 7) regarding each of the other design parameters (P2, P3 . . . Pn) to afford optimum values for all the design parameters;
• and
• 9) manufacturing a product based on the optimum design parameters obtained after performing steps 1) to 8).

A system for manufacturing products having optimum design parameters, which comprises:

• means for designing trial products which is inputted with several levels of a plurality (n) of design parameters of a product and outputs a trial product design based on a prescribed orthogonal table;
• means for depicting characteristic curves which is inputted with evaluation values obtained by evaluation of a plurality (m) of evaluation items and depicting characteristic curves of the evaluation data for the values of design parameters;
• means for deducing optimum values which outputs optimum values of the design parameters from the characteristic curves depicted by the means for depicting characteristic curves and inputted design ranges;
• and
• computerized means for manufacturing a product according to the optimum design obtained.