2012 Volume 20 Issue 1 Pages 65-73
In a study of a new two-dimensional measurement scale configured with a commercial scanner and an in-house analysis program, a functionality evaluation of combined standard uncertainty and economic loss due to measurement was performed per JIS Z 9090-1991 : Measurement - General rules for calibration system. As a result, the effect of the new scale was quantified as a loss reduction of 36 yen per unit as compared to the current system. On the basis of this loss reduction, an evaluation of plant and equipment investment in this measurement scale was carried out in a prototype pass/fail test system used to inspect 400 units per year manufactured for in-house delivery, and the net present value method was used to make a decision on plant and equipment investment. From the prototype test system it was found that investment in the new system would exceed expected future gain, and the inappropriateness of the plant and equipment investment was clearly quantified in economic terms. In a case study applied to volume production inspection with a high production volume,the expected future payback exceeded the cost of investment in the new system,and it was shown that again exceeding the investment could be expected.
