Mohammad Saber Fallah nezhad; Yousof Shamstabar; Mohammad Mahdi Vali Siar
Abstract
The CCC-r chart is developed based on cumulative count of a conforming (CCC) control chart that considers the cumulative number of items inspected until observing r nonconforming ones. Typically, the samples obtained from the process are analyzed through 100% inspection to exploit the CCC-r chart. However, ...
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The CCC-r chart is developed based on cumulative count of a conforming (CCC) control chart that considers the cumulative number of items inspected until observing r nonconforming ones. Typically, the samples obtained from the process are analyzed through 100% inspection to exploit the CCC-r chart. However, considering the inspection cost and time would limit its implementation. In this paper, we investigate the performance of CCC-r chart with variable sampling interval (CCC-rVSI chart). The efficiency of CCC-rVSI chart is compared with fixed sampling interval (FSI) scheme of CCC-r chart (CCC-rFSI chart) and CCCVSI chart. The comparison results show that CCC-rVSI chart is more efficient than the CCCVSI chart in reducing the average time to signal (ATS) and also CCC-rVSI chart performs better than CCC-rFSI chart. In addition, some sensitivity analyses are performed to illustrate the effect of the input parameters on the performance of CCC-rVSI chart.
M.S. Fallahnezhad; V. Golbafian
Volume 3, Issue 2 , December 2016, , Pages 1-16
Abstract
CCC-r chart extended approach of CCC charts, is a technique applied when nonconforming items are rarely observed. However, it is usually assumed that the inspection process is perfect in the implementation control charts imperfect inspections may have a significant impact on the performance of the control ...
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CCC-r chart extended approach of CCC charts, is a technique applied when nonconforming items are rarely observed. However, it is usually assumed that the inspection process is perfect in the implementation control charts imperfect inspections may have a significant impact on the performance of the control chart and setting the control limits. This paper first investigates the effect of inspection errors on the formulation of CCC-r chart, then an economic model is presented in the presence of inspection errors to design control chart so that the average cost per item minimized. The r parameter in the chart is optimized with respect to the economic objective function, Modified Consumer Risk, and Modified Producer Risk.