Optimal Designs of Synthetic and Double Sampling np Charts Based on Median Run Length and Expected Median Run Length

This study proposes six new np control charts with improved shift detection efficiency. The results gathered indicate that most of these new charts perform better than competing charts. Results obtained also provide major contributions to both academia and industry, providing attribute SPC practitioners with useful advice for selecting the most appropriate chart and paving the way for a new frontier of attribute SPC study. In addition to laying the groundwork for the design process and evaluation of attribute control charts, the findings of this study support the use of attribute control charts in a broad range of applications.