Concentrating on Whey: The Use of Statistics in Process Control

Author:	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
Topical Area:	N/A
Educational Level:	Undergraduate upper division, Graduate, Continuing education
Formats:	PDF
Type/Method:	Analysis (Issues), Discussion, Interrupted
Language:	English
Subject Headings:	Food Science / Technology Statistics
Date Posted:	12/19/2014
Date Modified:	N/A
Copyright:	Copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

Teaching Notes

Case teaching notes are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering here.

Teaching notes are intended to help teachers select and adopt a case. They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources.

Download Teaching Notes

Answer Key

Answer keys for the cases in our collection are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering here.

Get Answer Key

Name:
Email:
Department:
Institution:
City State:
Comments:
	Enter Security Code: