品質管制方法在實際應用時，常常存在顯著的測量誤差，但我們發現在許多多變量變異管制的方法中，會出現品質特徵含有測量誤差時的偵測效力大於沒有測量誤差時的偵測效力的現象。因為不含測量誤差的品質特徵比含有測量誤差的品質特徵擁有更多的資訊，所以這是一個奇怪的現象，但是文獻上並沒有針對這些監控多變量製程變異方法所產生的奇怪現象進行較詳細的探討。本文將研究測量誤差對於一般常用來監控多變量製程共變異數矩陣管制圖，包括修正概似比檢定、廣義共變異數矩陣、迴歸調整變數及主成分標準化變異和所建構之管制圖，的影響，並將對這種奇怪的現象做完整地分析討論，同時也將提出一種不會出現此奇怪現象的管制方法來監控多變量製程的變異。

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