QUALITY ASSESSMENT MODELS FOR INITIAL PRODUCTION PROCESS-CONTROL BASED ON STOCHASTIC DIFFERENTIAL-EQUATIONS

It is of great importance to assess an initial production process prior to the regular mass-production. For this purpose, many statistical methods have been proposed for practical use. In this paper, we propose two stochastic models for an assessment method of the initial production process control: a Markov process model and a Markov approximation model. These models are continuous state space models and formulated by applying mathematical techniques of stochastic differential equations. Based on each model, we derive several quantitative assessment measures for initial production process control.