Six Sigma

The Problem

A company which supplies parts and services has certain requirements from its customers, which include low cost, reliable assemblies, and on-time delivery. While all three factors are important to both the supplier and the customer, the customer has identified delivery time as their primary concern since they do not have the resources to handle the variation. The supplier is late far too often, and if the supplier ships the assemblies too early, it causes problems for the customer. As such, the company wishes to use a Six Sigma approach to reduce variability in delievery times. Six Sigma is a term for various coroporate strategies used to lower variation and unpredictability in some aspect of a product.

The company held an internal meeting to improve their delivery process. They defined a measurement, �Customer Delivery,� which is the number of days between when a shipment is promised and when it is actually shipped. The measurement is positive number if the shipment is late and is negative if the shipment is early. At the meeting, the company discussed what they can measure at their facility as a predictor of Customer Delivery. Students will mathematically identify which factors contribute to variation in Customer Delivery and produce a set of recommendations for the company to reduce that variation.

Areas of Application

Regression
Statistics - histogram, mean, standard deviation, correlation plot
Excel
Mini-Tab (optional instead of Excel)

Explanation of Alignment with Standards

Background Information

Since the supplier has decided that Customer Delivery has the highest priority in keeping their customers satisfied, the supplier would like to explore the various factors that cause the variability in Customer Delivery and determine mathematically which, if any, can be controlled. The delivery dates acceptable to the customer are in the time frame of 10 days early and 20 days late 95% of the time.

DMAIC - pronounced "Duh-May-Ick" - refers to a data-driven quality strategy for improving processes, and is an integral part of the company's Six Sigma Quality Initiative. DMAIC is an acronym for five interconnected phases: Define, Measure, Analyze, Improve, and Control

Define: Define who customers are, what their requirements are for products and services, and what their expectations are
: Define project boundaries, the stop and start of the process
: Define the process to be improved by mapping the process flow

Measure: Develop a data collection plan for the process
: Collect data from many sources to determine types of defects and metrics
: Compare to customer survey results to determine shortfall

Analyze: Identify gaps between current production and goal performance
: Prioritize opportunities to improve
: Identify sources of variation

Improve: Create innovative solutions using technology and discipline
: Develop and deploy implementation plan

Control: Prevent reverting back to the "old way"
: Require the development, documentation and implementation of an ongoing monitoring plan
: Institutionalize the improvements through the modification of systems and structures (staffing, training, incentives)

From GE's DMAIC Approach,

http://www.isixsigma.com/dictionary/DMAIC-57.htm

Materials Included

There are two versions of this project, the first for algebra students and the second for statistics. Both are available for download below, along with the appropriate Excel files.

DataFile.xls
GageRR.xls
MSAResults.xls
ICD.xls

Additionally, an optional extension to the project delves more deeply into some of the decision-making processes outlined in the main project. The extension is appropriate for both the Algebra and Statistics versions.

Download

Download the complete Algebra unit here:	File Name	Size
Compressed Zip File	Six Sigma for Algebra.zip	33k

Download the complete Statistics unit here:	File Name	Size
Compressed Zip File	Six Sigma for Statistics.zip	581k

To Download:

Windows: right-click on the filename above and choose: "Save Target As..."

Mac/Apple: hold the CTRL key, click on the filename above, and choose: "Download to Disk..."

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Last modified: Jun 25, 2010, 14:59 UTC