Title: Integrated SPC-based scheme utilising variable control charts and C_pm ratio to improve manufacturing quality of empty hard gelatin capsules

Authors: Omar Bataineh; Abdullah Al-Dwairi

Addresses: Department of Industrial Engineering, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110, Jordan ' Department of Industrial Engineering, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110, Jordan

Abstract: Quality control and improvement at the process level is a vital activity for the achievement of quality in products and services. This paper presents a three-phase scheme based on statistical process control methodology that employs variable control charts and process capability indices for quality improvement. The control charts employed are X-bar, s and the exponentially weighted moving average. The centred process capability ratio (C_pm) is employed for process capability assessment. The scheme accounts for both short-term and long-term changes in process performance and it is designed for a structured and less-complex implementation of control charts and process capability assessment. The proposed scheme has been implemented to the manufacturing process of empty hard gelatin capsules as a case study. This implementation has led to an expected reduction in the number of defective capsules by 29% relative to the stage before implementation.

Keywords: SPC; statistical process control; control charts; process capability indices; EWMA; exponentially weighted moving average; quality control; manufacturing quality; empty capsules; hard gelatin capsules; quality improvement.

DOI: 10.1504/IJPQM.2012.046366

International Journal of Productivity and Quality Management, 2012 Vol.9 No.3, pp.332 - 351

Published online: 31 Oct 2014 *

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