Using probability table in process quality control in special steel enterprises

摘要

Probability table (quality predict probability table) is made on the basis of regression analysis and square-error analysis according to the theory that the dependent variables exhibit a normal distribution witht he predicted value Y as the center, and its standard root-mean-square deviation sigma can be replaced by S (the residual root-mean-square deviation of the regression equation calculated according to the big sample) approximately. Each predicted Y can get the proper probability of certain characteristic value which meets with technical standard. These probability values compose a table, that is the quality prediction probability table (probability table in short). This paper discusses the following aspects on the basis of enterprise practice using probability table in process quality control in special steel enterprises.