TY - JOUR
T1 - Economic design of EWMA control charts using regions of maximum and minimum ARL
AU - García-Díaz, J. Carlos
AU - Aparisi, Francisco
N1 - Funding Information:
We would like to acknowledge the helpful comments of the anonymous reviewers. The authors acknowledge the financial support of the Ministry of Education and Science of Spain, Research Project Reference DPI2002-03537 and European FEDER funding. In addition, the authors would like to thank the Foreign Language Co-ordination Office at the Polytechnic University of Valencia for their help in translating this paper.
PY - 2005/11
Y1 - 2005/11
N2 - Nowadays, it is common to find industries that utilize processes that either have a value of the process capability index C pk larger than two or are very difficult to adjust. In these cases, the detection of very small shifts may not be of interest due to the possible extra variability introduced into the process by the detection process. It would be more interesting in these situations to decide what shift size is important for detection, and to design a chart capable of quickly detecting this shift whilst having a low probability of false alarms for the shifts that we do not wish to detect. The Exponentially Weighted Moving Average (EWMA) control chart, although originally developed to successfully detect small shifts, can be designed to cope with these requirements. This paper presents a method for the economic-statistical design of EWMA charts for control processes, in which the detection of small shifts is not necessary, and which is, at the same time, effective in detecting important shifts. A genetic algorithm is used to optimize the design. A sensitivity analysis of the optimal solution is performed to determine the influence of certain factors on the economic model.
AB - Nowadays, it is common to find industries that utilize processes that either have a value of the process capability index C pk larger than two or are very difficult to adjust. In these cases, the detection of very small shifts may not be of interest due to the possible extra variability introduced into the process by the detection process. It would be more interesting in these situations to decide what shift size is important for detection, and to design a chart capable of quickly detecting this shift whilst having a low probability of false alarms for the shifts that we do not wish to detect. The Exponentially Weighted Moving Average (EWMA) control chart, although originally developed to successfully detect small shifts, can be designed to cope with these requirements. This paper presents a method for the economic-statistical design of EWMA charts for control processes, in which the detection of small shifts is not necessary, and which is, at the same time, effective in detecting important shifts. A genetic algorithm is used to optimize the design. A sensitivity analysis of the optimal solution is performed to determine the influence of certain factors on the economic model.
UR - http://www.scopus.com/inward/record.url?scp=29144503359&partnerID=8YFLogxK
U2 - 10.1080/07408170500232214
DO - 10.1080/07408170500232214
M3 - Article
AN - SCOPUS:29144503359
SN - 0740-817X
VL - 37
SP - 1011
EP - 1021
JO - IIE Transactions (Institute of Industrial Engineers)
JF - IIE Transactions (Institute of Industrial Engineers)
IS - 11
ER -