X Charts with Variable Sampling interval and Warning limits
نویسنده
چکیده
The idea of variable sampling interval and warning limits (VSIWL) is proposed for X charts. Expressions for the performance measures for the charts with VSIWL are developed. The methods presented are general and can be applied to other Shewhart control charts. The performances of VSIWL X charts are compared numerically with that of VSI X charts with and without runs rules for switching between sampling interval lengths. It is observed that in general the former charts perform significantly better than the later.
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