Construction of control charts based on six sigma initiatives for fraction defectives with varying sample size

摘要

Purpose: To propose control charts for fraction defectives with varying sample size, suitable for organizations practicing Six Sigma and have achieved lower defective rates. Summary: The companies who have implemented Six Sigma methodology would have achieved 3.4 defectives or less per million and hence application of conventional Shewhart control chart. Sampling plans have been introduced for such situations single, double or repetitive sampling plans indexed through Six Sigma quality levels with Poisson distribution as baseline distribution. This paper proposes a control chart for Six Sigma initiatives with varying sample size for fraction defectives.