AN ALTERNATIVE METHOD TO TEST FOR RANDOMNESS OF A PROCESS

摘要

The objective of this paper is to revisit an old technique for testing the randomness of a process. This method uses the mean square successive difference approach to estimate variance, compares this estimate with the usual variance estimate, and tests whether the two variance estimates are significantly different. If the test result is significant, it is concluded that the process is not random (i.e. not in control). The non-random results are addressed to accomplish quality improvement.