An Extension of Economic Design of x-Bar Control Charts for Non Normally Distributed Data Under Weibull Shock Models

Abstract

Three parameters—sample size, sampling intervals, and the control limits—must be determined when the x bar chart to monitor a manufacturing process. The constant sampling intervals were widely employed because of its administrative simplicity. However, the variable sampling interval (VSI) has recently been shown to give substantially faster detection of most process shifts than fixed-sampling-interval (FSI) for x-bar charts. In addition, these measurements in the subgroup are assumed to be normally distributed. That assumption may not be tenable. This investigation compares the economic design of x-bar control charts for non normal data under Weibull shock models with various sampling avenues.

Keywords:

• Burr distribution
• Economic design
• Variable sampling interval
• Fixed sampling interval
• Non normal distribution

Mathematics Subject Classification:

• 90C30
• 34A34

Notes

# Represents using the variable sampling interval method. * Represents using the fixed sampling interval method.

# Represents using the variable sampling interval method. * Represents using the fixed sampling interval method.

() Represents utilizing fixed sampling interval scheme.

() Represents utilizing fixed sampling interval scheme.

() Represents utilizing fixed sampling interval scheme.

() Represents utilizing fixed sampling interval scheme.

() Represents utilizing fixed sampling interval scheme.