A pattern recognition algorithm for an (x)over-bar control chart

Control charts are very useful in identifying process problems. With the implementation of automated data collection methods and computerized plotting on control charts, a need exists for identification procedures that can alert the operator to unnatural patterns and special causes. This proposed pattern-recognition algorithm is based on traditional recognition methods modified for recognizing nonrandom patterns on an (x) over bar control chart. Extensive simulations tested the capability of the algorithm to detect cycles and systematic patterns on an (x) over bar control chart. Average run lengths are computed and compared with other relevant studies. Extensions and enhancements are also addressed.