動態製程管制之研究

Abstract

本研究提出製程上特殊因的發生服 從多個韋伯分配的監控方法。它能有效區 分是製程平均數或變異數是失控的，以使 失控的製程迅速回復穩定中。 X-bar 管制 圖和 S 控管制圖分別被發展以能經濟有 效 的 管 制 製 程 並 顧 及 顧 客 對 品 質 的 聲 音。資料模擬結果說明這些管制圖的建立，應用及參數之敏感度。另外，製程上多元 製程變數的追蹤也考慮製程上特殊因的 發生服從多個韋伯分配的情形，多元管制圖被發展以能經濟有效的管制製程並顧 及顧客對品質的聲音。資料分析結果說明 這 些管制圖的建立，應用及參數之敏感 度。

The study considers the adaptive statistical process control for two dependent process steps. There are three topics in the study. First, we propose the two adaptive sampling interval control charts to monitor and distinguish two dependent process steps effectively. The performance is measured by average time to signal (ATS) which is derived by Markov chain approach. The performance of the ASI control charts is compared with FSI control charts. It is demonstrated that the ASI control charts outperforms the FSI control charts. Some sensitivity analysis illustrates the effects of process parameters on the ATS. Second, the adaptive sample size control charts are derived to monitor and distinguish the two dependent process steps effectively. Its performance is also measured by average time to signal (ATS) which is derived by Markov chain approach. The performance of the ASS control charts is compared to the FSS control charts. It is demonstrated that the performance of the ASS control charts is much better than the FSS control charts. Sensitivity analysis illustrates the effects of process parameters on the ATS. Third, we combine the adaptive sample size and adaptive sampling interval to derive the ASSI control charts to monitor and distinguish two dependent process steps effectively. Its performance is also measured by average time to signal (ATS) which is derived by Markov chain approach. The performance of the ASSI control charts is compared with FSSI control charts. It is demonstrated that the ASSI control charts is much better than the FSSI control charts for very small shifts in process mean, but the performance of FSSI control charts is better than ASSI control charts for moderate shifts in the process means.