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Taguchi Gen'ichi introduced Mahalanobis-Taguchi System (MTS) which is in combination with the concepts of quality engineering and Mahalanobis Distance (MD). The MTS is proposed as diagnosis and forecasting method using multivariate measurement scale with its intention to help policy maker as basis for decision making. This study applies MTS approach in a manufacturing process to reduce a set of parameters, at the same time there will be a pattern, which can forecast and identify important parameters, constructed by MTS method. Through this pattern can minimize unimportant inspection in process and save unnecessary time and cost. The primary goal to structure a measuring scale which makes accurate forecasting in multidimensional system. The case study in this paper reviews the planarity of back-end process in 8-inch silicon wafers on the purpose to construct a pattern of reduced set of parameters. In this paper, using thirty-two current variables as reference space and furthermore reducing the variables to seven parameters in order to predict defective items. As a result, it has still good discriminant accuracy. If validation of the reduced-set parameters is reliable with its good discriminant accuracy, it means that the company in this case study can built defective items warning of the pattern parameters in back-end process because this approach of selecting parameters is feasible.

Based on the proppant index, a production forecast method for thick oil-bearing formation fracturing was deduced. And combined with NPV methodology, treatment scale of multistage pump-off propped fracturing can be optimized. The effects of treatment parameters, such as injection stages, pumping interval, pumping rate, the ratio of pre and post stage pumping rate, on the fracture geometry, conductivity and production were simulated and analyzed. It reveals that two injection stages, 5 minutes of pumping interval and consistent pumping rate contribute to the highest annual cumulative production. Moreover, the injection stages make the most significant influence on production. Optimization results, applied to Kunbei Oilfield, achieved satisfactory application effects. The single well average production was enhanced by7.92 t/d, the stimulation ratio was 13.56, and the stimulation validity was about 270 days.