Title: Evaluating multi-objective economic-statistical design of attribute C control charts for monitoring the number of non-conformities
Authors: Amirhossein Amiri; Samrad Jafarian-Namin
Addresses: Industrial Engineering Department, Faculty of Engineering, Shahed University, Khalije Fars Highway, Tehran, P.O. Box 18151-159, Iran ' Department of Industrial Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
Abstract: The C control chart is mostly used to monitor the number of non-conformities per inspection unit of constant size. It is known that the classic C-chart control limits often experience a high false alarm rate and thus lead to the increase of unnecessary costs of inspection. Among many works performed to improve C-charts, this paper presents the optimised control limits approach to the C-chart. In addition, different C-charts are evaluated through factors related to the design of the control chart. Optimally selecting design parameters depends on several process parameters from statistical and/or economic aspects in the literature. This study presents multi-objective economic-statistical design of different C control charts under single assignable cause. An algorithm using the data envelopment analysis (DEA) is employed to solve the models. A numerical example is used to illustrate the algorithm procedure and to evaluate the performances of different designs.
Keywords: C control charts; optimisation; control limits; single assignable cause; multi-objective design; economic-statistical design; data envelopment analysis; DEA; SPC; statistical process control; process monitoring; nonconformities; C-charts.
International Journal of Quality Engineering and Technology, 2015 Vol.5 No.2, pp.145 - 161
Received: 18 Feb 2015
Accepted: 10 May 2015
Published online: 09 Sep 2015 *