@article{MAKHILLJEAS201611713757, title = {Effects of Misspecification on the Economic-Statistical Design of the Coefficient of Variation Chart}, journal = {Journal of Engineering and Applied Sciences}, volume = {11}, number = {7}, pages = {1655-1659}, year = {2016}, issn = {1816-949x}, doi = {jeasci.2016.1655.1659}, url = {https://makhillpublications.co/view-article.php?issn=1816-949x&doi=jeasci.2016.1655.1659}, author = {Yeong Wai,Michael Khoo Boon,Lim Sok,Teoh Wei and}, keywords = {Coefficient of variation chart,economic-statistical design,incorrect specification,increase in cost,rough approximation}, abstract = {The Coefficient of Variation (CV) chart monitors changes in the ratio of the standard deviation against the mean, instead of monitoring changes in the mean and/or standard deviation. The economic-statistical design of the CV chart allows practitioners to select optimal chart parameters which minimize the cost subject to constraints in the run length. However, a large number of parameters need to be estimated. This study looks at the effects when these parameters are incorrectly estimated. It was found that a minimal increase in cost is shown when the parameters are not estimated accurately, except for the incorrect specification of the shift size and the out-of-control quality cost which shows a slightly higher increase in cost. Thus, only a rough approximation is needed for most of the parameters.} }