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Concentrating on Whey: The Use of Statistics in Process Control


Author(s)

Helen S. Joyner
School of Food Science
University of Idaho
hjoyner@uidaho.edu

Abstract

This interrupted case study follows the progress of Kenny, the head operator for a whey protein processing system, as he works with Cheryl, a quality management specialist, to implement control charts to monitor process variables. Students assume the role of Cheryl as she shows Kenny how to create a control chart, explains the different types of out-of-control behaviors seen in control charts, and demonstrates how to calculate process capability and capability index.  Kenny uses this information to determine a probable cause of variation. Originally developed for a senior-level undergraduate statistical quality management course, this case study is also appropriate for courses focusing on quality management in industrial settings, as well as for a general undergraduate statistics course. Although familiarity with HACCP (Hazard Analysis Critical Control Points) principles is assumed, students are not expected to know about whey protein processing fundamentals.


Objectives

  • Differentiate between variables and attributes.
  • Differentiate the appropriate uses for Xbar, R and s charts.
  • Select the appropriate quality characteristic(s), rational subgroup, and sampling method for a given process.
  • Construct and revise variable and attribute control charts.
  • Evaluate control charts for out-of-control patterns.
  • Explain why a given process is in control or out of control.
  • Calculate process capability and process capability index and explain what the results mean in terms of process control.
  • Calculate the quality rating of a product and explain what the results mean in terms of process contro.

Keywords

Quality management; quality rating; process control; process capability; capability index; control chart; variables and attributes; sampling method; food safety; food quality; whey

Educational Level

Undergraduate upper division, Graduate, Continuing education

Format

PDF

Type Methods

Analysis (Issues), Discussion, Interrupted

Language

English

Subject Headings

Food Science / Technology  |   Statistics  |  


Date Posted

12/19/2014

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