Case Studies and White Papers

Published: October 2006
Authors: Patrick Whitcomb, Mark Anderson

This mini-paper, provided on pages 5-8 in the publication via the link above*, addresses concerns about mixture designs coming up short on power. *(Manuscript available under Download link below.)

Publication: ASQ Statistics Division Newsletter

Published: September 2006
Authors: Fabio Leao, Ian Pashby, Patrick Whitcomb, Martyn Cuttell, Peter Lord

EDM fast hole drilling is one of the most important variations of electrical discharge machining. The process plays an important role in the aerospace industry as it is one of the few that can be applied to the drilling of precision small holes in a number of parts, including turbine blades. One of the most important factors affecting the speed of EDM fast hole drilling is the high pressure dielectric fluid, which is usually supplied to the gap through the bore to tubular electrodes. Thus, it can be expected that the bore size and geometry have a great impact on the process performance. However, there has not been much research on this topic. By employing statistical methods to optimise the process performance, this work shows that drilling time and electrode wear can decrease 165% and 25% respectively, depending on the type of electrode geometry used.

DOE for Coatings

Published: August 2006
Authors: Mark Anderson, Patrick Whitcomb

This article provides an introduction to design of experiments (DOE) for improvement of coatings processes and formulations. It includes a case study on a spin-coater.

Publication: Coatings Technology Handbook, 3rd Edition

PCR Process Optimized via Split-Plot DOE

Published: May 2005
Authors: Patrick Whitcomb, Shari Kraber

This paper illustrates the use of design of experiments (DOE) and split-plot design to quickly and effectively determine the factor settings that maximize amplification in a polymerase chain reaction (PCR) experiment.

Publication: 2005 ASQ World Congress

Screening Process Factors In The Presence of Interactions

Published: May 2004
Authors: Mark Anderson, Patrick Whitcomb

This article introduces a new, more efficient type of fractional two-level factorial design of experiments (DOE) tailored for the screening of process factors. These designs are referred to as Min Res IV.

Publication: AQC 2004 Toronto

How to Use Graphs to Diagnose and Deal with Bad Experimental Data

Published: May 2003
Authors: Mark Anderson, Patrick Whitcomb

This article deals with thorny issues that confront every experimenter how to handle individual results that do not appear to fit with the rest of the data. (A somewhat modified version of this article was published in Quality Engineering. April 2007.)

Publication: ASQ Kansas City Annual Quality Congress

Published: October 2002
Authors: Mark Anderson, Patrick Whitcomb

This article offers a simple case study that illustrates how to put rubber or plastics formulations to the test by using powerful statistical methods for mixture design and analysis. Rubber & Plastics News.

Publication: Rubber & Plastics News

Published: October 2002
Authors: Gary Oehlert, Patrick Whitcomb

This technical paper details a new class of high-resolution (V) minimum-run two-level factorial designs that characterize two-factor interactions with far fewer runs than classical templates. These "MR5" designs serve well as the core for central composite designs that reduce the number of runs needed for response surface methods.

Publication: Fall Technical Conference 2002

Published: July 2001
Authors: Gary Oehlert, Patrick Whitcomb

Power tells us the probability of rejecting the null hypothesis for an effect of a given size and helps us select an appropriate design prior to running the experiment. This paper describes a general approach for sizing effects that covers a wide variety of designs. Quality and Reliability Engineering International.

Publication: Quality and Reliability Engineering Intl.

How to Save Runs, Yet Reveal Breakthrough Interactions, By Doing Only a Semifoldover on Medium-Resolution Screening Designs

Published: May 2001
Authors: Mark Anderson, Patrick Whitcomb

Via case studies, this paper reviews the strategy of foldover on low-resolution (III) two-level fractional factorials and demonstrates how to reduce experimental runs by making use of semifoldover methods to augment medium-resolution (IV) designs.

Publication: ASQC 55th Annual Quality Congress Proceedings