Control diagram of Robust for dispersion monitoring.

Abstract

A production process control method or technique used is control diagram of Shewhart. There are some dispersion control diagrams for variable characteristic, they are a distance (D) and standard deviation (SD). Both are made under assumption of normal distribution process. When the normality assumption is broken, the performance of both control diagrams are decreased. (no robust on  terhadap normality). This study describes dispersion control diagram of robust (free from distribution) with non-parametric method approach. The statistic based on Mood test statistic on each individual sample ( n = 1) for every period. Therefore, the objective of this study is to describe control diagram procedures of robust for dispersion process monitoring and how to implement them.