Fluidic type gas meters have a potential to be miniaturized compared with the traditional film type meters. Therefore, its adoption could improve the street appearance and ease the installation of equipment. In order to optimize this fluidic type gas meter design, the generic function was determined to maximize the linearity between gas flow and oscillating frequency. From the study, it was found that the depth of end-block is the most important factor to maximize the linearity. It was also found that target width is important to pulse oscillating strength.

Compact dual tubes are used for exhaust gas systems in automobiles. A dual tube has a divider in a single tube to provide two paths to replace the traditional two independent tubes. The former has advantages of low cost, less material and more available space, etc. Quality engineering was applied and a stable and optimized laser welding condition was found in a short period of time.

Our company has developed a new Quality Engineering training Program for beginners. The existing training methods are mostly "confirmation and correction" oriented. Instead, the new program aims an experimental learning process and the lecture through functional evaluation and parameter design using orthogonal arrays. The course can be completed in eight hours. Many control factors were provided for selection by the trainees. An L18 orthogonal array experiment can be completed in an hour.

The quality of rubber sponge used for cars is greatly affected by the variability of ingredients and manufacturing conditions. It is the variation of compression load deflection which is the quality characteristic used to evaluate door closing and sealing functions. There are two kinds of causes: shape related and material related. In this report, material related cause was studied to reduce variability through the examination of the SN ratio which is calculated from the correlation between the compressed amount and compression load deflection. The curves due to the correlation showed non-linearity. The compression rate and reciprocating paths cause differences in the compression load deflection. Since these phenomena are the characteristics needed for rubber products, the quadratic term was studied.

As a result, 62.6% variability reduction was obtained for the case when all non-linear terms were considered as the error, and 62.8% variability reduction was resulted for the case when the quadratic term was not considered as the error. Further more, by studying the sensitivity of quadratic terms, the trends of processing conditions that affect the compression rate or the reciprocating paths of compression were found to be similar. That made possible to intentionally utilizing the hysteresis phenomenon.

Cam-shaft is one of the most important component parts in the engine that drives the intake and exhaust valves. It is required that the cam dimensions are accurate and its surface be smooth. It is also important to reduce cost while maintaining high quality during mass production. Simulation was used in the study. Nominal-the-best characteristic was used to achieve a targeted Raynold's number. After the optimization, the occurrence of defects was reduced and it was proven that this approach was effective. It was also expected that the production preparation period can be shortened.

Summary Taguchi Methods, also called Robust Design, have been successfully applied in many engineering applications to improve the performance of the product/process. These methods are proved to be extremely useful and cost effective. In this paper we will describe how Taguchi Methods are useful in multidimensional system applications. We use Mahalanobis distance (MD) for constructing a measurement scale for the multidimensional systems and the principles of Taguchi Methods for optimizing the system. Therefore, we refer to this procedure as the Mahalanobis-Taguchi-System (MTS). The measures and methods used in MTS are data analytic rather than usual probability based inference. In this paper, a detailed procedure of MTS is explained with two case studies.