Interpreting patterns and setting up charts

Abstract

The previous two chapters have referred constantly to the need to interpret charts. There has been an emphasis on using the four rules to determine the presence of special causes which should then be eliminated, or permanently incorporated, depending on their nature. Fig. 8.1 illustrates the types of pattern which indicate improvement in the process. Patterns other than these are connected with special causes which adversely affect the current situation and would therefore result in poorer process performance.