| 摘要 |
<p>PROBLEM TO BE SOLVED: To analyze the correlation between process control data and quality data, which can not be obtained by a scatter diagram or a correlation coefficient. SOLUTION: In a iron and steel process, the range of values that can be taken by a manufacturing line velocity V in a certain manufacturing period is divided into L pieces of ranges, the probability distribution Pi of the number N of surface faults is calculated in each range (i), and the number NiPc of fault occurrences, where a prescribed cumulative probability in each range (i) becomes Pc is calculated. The relation between the manufacturing line velocity V and the number NiPc of surface faults to be the prescribed cumulative probability is expressed by an approximate expression or a table, an appropriate manufacturing line velocity to obtain a product with few surface faults is obtained and the maximum number of surface faults of a product, which occurs in the probability Pc is predicted in the case of being a certain manufacturing line velocity by using the approximate expression or the table.</p> |
