Cumulative sum charts for high yield processes

The cumulative sum (CUSUM) chart, well-known to be sensitive in detecting s mall and moderate parameter changes, is proposed here for monitoring a high yield process. The sensitivities of the CUSUM charts based on geometric, B ernoulli and binomial counts axe compared. Based on the comparisons, recomm endations for the selection of a chart are provided. Simple procedures axe given for optimal design of CUSUM charts based on geometric and Bernoulli c ounts. An application of CUSUM charts in monitoring an actual high yield pr ocess is demonstrated.