| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To enable alarm standards to be easily set up in Shewheart control chart. <P>SOLUTION: A quality control method includes a step (S102) of calculating the mean value X and standard deviationσof quality control data; a step (S106) of removing abnormal data out of a region of mean value×±4σ; a step (S108) of calculating the degree of estrangement between the calculated means value X, where the abnormal data have been removed and a usual target value by the use of the standard deviationσ; a step of calculating N so as to set the ratio of the number of data out of a region of a reference value±(2.5+0.1×N)σto all the number of data at 0.015 or below:1, where the calculated mean value is made to serve as the reference value when the degree of estrangement is large, or a usual target value is made to serve as the reference value when the degree of estrangement is small; a step of setting up a reference value±(2.5+0.1×N)σas alarm standards; and a step of forming quality alarm information when data out of the alarm standards appear. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
