VarTran User Guide - Variation.com

1 V AR T RAN WORST-CASE TOLERANCES ml/min LSL T USL STATISTICAL TOLERANCES ml/min LSL T USL ROBUST DESIGNS Temperature Hot Bar ( F) Dwell Time (sec) 200 175 150 SEAL STRENGTH STANDARD DEVIATION o CAUSE OF VARIATION T R A N S M I T T E D V A R I A T I O N X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 user 's Guide VVAARRTTRRAANN Version Dr. Wayne A. Taylor Copyright 2004 Taylor Enterprises, Inc. All Rights Reserved. Taylor Enterprises, Inc. 5510 Fairmont Road, Suite A Libertyville, IL 60048 (847) 367-1032 Fax: (847) 367-1037 E-mail: Web: VarTran is a registered trademark of Taylor Enterprises, Inc. This software package was created by: Dr. Wayne A. Taylor Dr. Taylor is the founder and chairman of Taylor Enterprises, Inc. where he is responsible for the development of the VarTran , Change-Point Analyzer, and Sampling Plan Analyzer software packages as well as providing consulting and training on the Six Sigma approach and tools including Robust Design, Tolerance Analysis, Design of Experiments, SPC, Acceptance Sampling, and Statistics.

2 Dr. Taylor retired from his position as Director of Quality Technologies at Baxter Healthcare Corporation where he was responsible for implementing Baxter's Six Sigma program. He had been with Baxter for 22 years. Dr. Taylor is author of the books Optimization and Variation Reduction in Quality and Guide to Acceptance Sampling. The first book outlines the approach implemented at Baxter for achieving six sigma quality. The second book provides an easy to use approach for selecting valid sampling plans and for reducing inspection costs that has saved Baxter over 30 million dollars annually. His two courses Successful Acceptance Sampling and Robust Tolerance Analysis have been attended by thousands of engineers and scientists. Dr. Taylor is a leading expert on acceptance sampling and process validation in the pharmaceutical, medical device and diagnostics industries.

3 His articles on selecting statistically valid sampling plans have become standards in the industry. He is one of the authors of the Global Harmonization Task Force guideline on Process Validation. The VarTran software and Dr. Taylor's course Robust Tolerance Analysis have rapidly become a key component of many companies DFSS (Design for Six Sigma) programs. Honeywell, the Six Sigma Academy and numerous other companies have adopted VarTran as an essential tool for designing high quality products. Dr. Taylor received his in Statistics from Purdue University. He is a fellow of the American Society for Quality. Table of Contents Chapter 1 Program Installation 1 System Requirements 1 Installation VarTran 1 Registering the Software 2 Uninstalling VarTran 2 Chapter 2 Tutorials 3 Design of a Pump 4 Optimization of a Heat Sealer 12 Dimensional Stack-Up Problem 20 VarTran as a Mathematics Package 28 Chapter 3 Overview 33 Optimization & Variation Reduction 33 The Importance of Reducing Variation 35 How to Reduce Variation 37 Robustness 40 Variation Transmission Analysis 43 Behavior of the Inputs 44 Strategy 48 Chapter 4 Entering Information 49 Main Window 49 Adding Variables 50 Continuous Input Variables 51 Category Input Variables 61 Output Variables 63 Objective

4 Functions 70 I/O System Window and Editing Variables 74 Summary Table 76 Chapter 5 Predicting Capability 79 Capability Study Window 79 Cp, Cc, Cpk and Six Sigma 81 Statistical Tolerances 90 Worst-Case Tolerances 94 Process Tolerances 97 Objective Functions 102 Table of Contents Chapter 6 Optimization and Robustness 103 Find Optimal Targets Dialog Box 103 Simplex Method 106 Interval Method 107 Optimization Options 109 Chapter 7 Tightening Tolerances 111 Pareto Chart Window 111 Working With More Than One Design 116 Chapter 8 Understanding the Results 121 Effects Tables 121 Plots Dialog Box 125 Plot Window 127 Checking Results Using Simulations 136 Chapter 9 Using VarTran with Designed Experiments 139 Types of Equations 139 Dual Response Approach 141

5 Tolerance Analysis Approach 143 Chapter 10 Menus and Toolbar 147 File Menu 147 Variables Menu 150 Analysis Menu 152 Window Menu 153 Options Menu 154 Help Menu 155 Toolbar 157 Glossary 159 References 169 Index 171 Program Installation 1 1 Program Installation This section describes the system resources required by VarTran and how to install VarTran on your computer. System Requirements VarTran runs on any 32-bit Windows operating system including Windows 95, 98, 2000, XP and NT.

6 It requires 5 MB of hard disk space to install. Installing VarTran VarTran is a shareware program. A full version of the software can be downloaded for a 30-day trial. If you want to continue using the software after trial period, you must register it. To install VarTran , download the file from Executing this file will run the installation program. The software will be automatically installed to the directory C:\Program Files\Taylor Enterprises\ VarTran . Along with the software, the user manual, a tutorial, and numerous example files are copied to this directory. VarTran data files end with the extension vta. A shortcut is added to the desktop for starting the program. It appears as below. Double clicking this shortcut will start the program. In addition, three menu items are added to Programs menu.

7 Click on the button in the lower left corner of the screen and then click on the Programs menu item. Find the VarTran folder and click on it. This displays the following three menu items: The third menu item starts the program. The first two menu items display program documentation in pdf format. You must have a copy of the free Adobe Acrobat Reader to view these files. 2 Chapter 1 Registering the Software VarTran can be used free of charge for 30 days. After the 30 days trial period, you must register the software to continue to use it. To register the software, go to and click the Register button.

8 Up to date pricing information will be provided along with further instructions. The registration process can be completed online. The Help menu of VarTran also contains further details about registering the software. Once the software is registered, you will receive a user name and registration code by email. These must be entered into the software. The user name and registration code can be manually entered into VarTran by selecting the Enter Registration Code menu item on the Help menu. This displays the Registration dialog box shown below. The user name and registration code must both be entered exactly as provided (case-sensitive). Once done, click the OK button. Uninstalling VarTran VarTran can be uninstalled using the Add or Remove Programs icon on the Control Panel.

9 Step-by-step instructions follow: Click the Start button. Select the Control Panel menu item from the Settings menu. Double click the Add or Remove Programs icon. Select the program VarTran and click the Change/Remove button. This will remove the program, user manual, tutorial and example files. It will not affect any files you created using the software. Tutorials 3 2 Tutorials VarTran has numerous capabilities. It can be used to perform tolerance analysis. VarTran performs both worst-case and statistical tolerancing. It can be used to solve tough nonlinear problems for which the classical tolerancing formulas fail. VarTran also implements an entirely new approach to tolerancing called process tolerancing.

10 This novel approach to tolerancing represents a unified approach that allows worst-case tolerances to be used for some variables, statistical tolerances for others and a combination of the two for the rest. Process tolerancing solves the age-old debate of worst-case versus statistical tolerances. VarTran , however, is much more than a tolerancing package. It can be used to reduce variation through robust designs. You can ask VarTran to find the set of targets that maximizes Cpk, minimizes the Taguchi loss or that achieves some other objective. You can then ask VarTran which tolerances contribute the most to the remaining variation so that tolerances can selectively be tightened based on cost and benefit. The result is high quality at a low cost. VarTran can be used in product design, process development, material development and manufacturing.