Attribute Control Charts with Optimal Limits

A new attribute control chart is presented to monitor processes that generate count data. The economic objective of the chart is to minimize the total cost of its errors, a linear function of errors Type I and II. The proposed chart can be applied to Poisson, geometric, and negative binomial assumptions. Control limits are calculated optimally, because they are based on exact probability distributions and used to detect defined directional shifts in a process. Some numerical results are provided, and expected costs of the new chart are compared with those of a one-sided c-chart. Other effects such as changing the cost structure are shown graphically. Copyright (c) 2015 John Wiley & Sons, Ltd.