The functional requirements in the heat treatment of metal molds are conformity of hardness to the target value and minimal distortion after the heat treatment. A manufacturer who outsources heat treatment can reduce post-processing costs and losses to consumers by choosing a heat treatment vendor based on a functional evaluation of its heat treatment technology, In this study, we performed a functional evaluation by using transferability to evaluate surface hardness and distortion after heat treatment, and used a loss function to select a heat treatment vendor.

Various instruments have been developed for correct and precise measurement. However, even when the same measuring instrument is used, different people have different ways of measuring, and the accuracy of the measurement valies accordingly. These individual differences are a basic problem in metrology. In this study, based on the result of a previous study which showed that a person's measurement ability often depends on the person's character, we evaluated and estimated the measuring ability of subjects from the measuring processes they used, to see if it would be possible in this way to obtain more reliable measurement values. The results indicated the possibility of estimating micrometer measuring ability by Taguchi methods just from the measurement process. It was also shown that measurement operations play a major role in reducing measurement error.

This study targeted a process in which the movable metal contact of a tact switch is inserted into a housing combi. In this process, the metal contact must be seeurely held by a vacuum nozzle and correctly inserted into the housing combi. Formerly, minor stoppages (unexpected short stops, occurred due to vacuum faults and contact insertion errors. Parameter design was performed in order to select optimal conditions to eliminate the insertion errors. As a result,occurrence of minor stoppages was reduced to one tenth.

In aircraft engines, shafts and other sliding members are plated with thick and very hard chromium layers to increase their resistance to wear. When nonconformities such as pits, cracks, or uneven plating have occurred in the chrome plating process, it has been difficult to assess the causes by conventional methods. In this study, we considered the generic function of plating and performed an optimization experiment by parameter design. As a result, compared with existing methods, variation was reduced to one fourth and productivity was doubled.

Two ideas for making higher-density magneto-optical disks were compared. The quality of ideas in this area affects two corporate divisions, the media division and the drive division, both of which are involved in optical disk development. For ease of tuning to target values, the comparison was made by use of simulation. In this study we were able to suggest the possibility of reduction in development cost by selecting a system after judging the quality of ideas from the standpoint of quality engineering.

Increasing quality and cost demands from the market require the cost of diecast products to be reduced. Net-shape technology is attracting attention as a means of reducing the cost of cutting in manufacturing processes. As it is difficult to eliminate cutting processes entirely at the current state of the art, what is important is to improve casting technology to a level that can minimize the amount of cutting. Therefore, in this study, optimization by CAE was used to obtain conditions that would require minimal shape modification after die-casting. An initial optimization was performed using the cooling tubing conditions and the settings of the die-cast machine as control factors, and the relations between the conditions were examined; the optimization process then focused on the cooling tubes. The results showed that the die-cast machine settings had a greater effect than the cooling tubing conditions, and that it is important to study the optimal cooling tubing conditions, which can be incorporated into the die design, from the viewpoint of total production cost.