Statistical Process Control Methods for Multiple Stream Processes: A Comparative Study

Authors

Jared Caleb Christensen, Brigham Young University
Dr. Scott D. Grimshaw, Brigham Young University

Keywords

control methods, multiple stream processes, Shewhart control chart

College

Physical and Mathematical Sciences

Department

Statistics

Abstract

The Shewhart control chart is the most common statistical process control (SPC) tool used to determine stability. One fundamental assumption of the Shewhart chart is that the output comes from a single, continuous stream. This implies the monitoring of a single source of variation. Filling machines at many beverage plants violate this assumption because there are central filling units with multiple heads filling individual bottles. The variability of the central filling units is the “natural, continuous variability” of the process in terms of a Shewhart chart. The heads add another source of variability. A different methodology needs to be implemented to effectively monitor both the process variability and the variability from each head. Different methods have been proposed to monitor both of these types of variability. This study examines the performance of multiple Shewhart charts, group control charts (with original and revised control limits), and a Hotelling’s T2 control chart using data from the BYU Creamery.

Recommended Citation

Christensen, Jared Caleb and Grimshaw, Dr. Scott D. (2014) "Statistical Process Control Methods for Multiple Stream Processes: A Comparative Study," Journal of Undergraduate Research: Vol. 2014: Iss. 1, Article 1293.
Available at: https://scholarsarchive.byu.edu/jur/vol2014/iss1/1293