SBS - The best value in QMS software

Quality Digest article - "An Honest Gage R&R Study" - Where is he getting the d2*?

D

dbulak

#1
I just received the on-line QualityDigest. In it it has what looks like a shotened version of Donald J Wheeler's March 2008, "An Honest Gage R&R Study. My question is where is he getting the d2* for the bias correction?
I looked in the MSA 4th edition and could not find the same numbers. Are there special calculations that have to made? Not totally familiar with all these formulas.

Thanks in advance.
 
Elsmar Forum Sponsor
S

Sturmkind

#2
Re: Quality Digest article - "An Honest Gage R&R Study"

Hi,' dbulak!

It's been awhile since I manually consulted the tables but perhaps the following helps.

The difference between d-sub-2 and d-sub-2-star is that "...the validity of the d2 factor assumes that the ranges have been averaged over a fair number of subgoups...20 or more. Where only a few subgroups are available, a better estimate is...d-sub-2-star...from the old Mil-414 of the U.S. Department of Defense..." Taken from page 128, Statistical Process Control 3rd ed. by Grant & Leavenworth. These tables also appear in A. J. Duncan, Quality Control and Industrial Statistics, 4th ed. p. 950 Richard D. Irwin, Inc., Homewood, IL., 1974.

I did compare the (Duncan)tables to MSA 4th and there are no significant differences to MSA 4th Edition after the number of subgroups > 1.

If samples are taken from a normal IIDU then the use of either is pretty neglible on the final GR&R results.

Thanks for bringing the topic up as it helps keep me fresh!
 
Last edited by a moderator:
D

dbulak

#3
Re: Quality Digest article - "An Honest Gage R&R Study"

I guess my problem is that when I look at the tables for d2* I do not find any numbers that are close to what he is using in his calculations. Except for d2 at 1.128, I am not seeing where they are coming from. I guess I am not looking in the correct spot.
 

Bev D

Heretical Statistician
Staff member
Super Moderator
#5
Re: Quality Digest article - "An Honest Gage R&R Study"

Its also important to remember that the R&R analyses are estimates. both d2 and d2* are not exact. in practical terms the of use d2 or d2* won't change the decisions to be made regarding the effectiveness of the system.

good question tho! there are lots of statistical quircks out there and too often they are shrouded in either mysticism or 'statistical correctness'.
 
Thread starter Similar threads Forum Replies Date
WCHorn Quality Digest article on the Process Approach to ISO 9001 ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 4
U 25 Problems Article from Quality Digest, by Jamie Flinchbaugh The Reading Room 1
Q Looking for a certain article in previous issues of Quality Digest World News 6
Crusader Internal Auditing for ISO/TS-16949 - Quality Digest article May 2006 General Auditing Discussions 1
Sidney Vianna Someone is threatening to sue Quality Digest over an old article World News 9
Marc Six Sigma Survey for November Quality Digest article Six Sigma 5
P A collection of Dr. Wheeler's Articles from SPC Toolkit column of Quality Digest Statistical Analysis Tools, Techniques and SPC 3
Q Quality Digest 2007 Salary Survey Available Online Career and Occupation Discussions 1
CarolX Seeking Trade Magazine (like Quality or Quality Digest) in Spanish Book, Video, Blog and Web Site Reviews and Recommendations 2
A New Quality Gurus? As listed by Quality Digest - A general Discussion Philosophy, Gurus, Innovation and Evolution 22
Wes Bucey Quality Digest Survey of ISO Registrants - 2004 - Client-registrar relationship Book, Video, Blog and Web Site Reviews and Recommendations 0
Marc Quality Digest 2004 Salary Survey - Yearly Elsmar Cove Poll - Where do YOU stand? Career and Occupation Discussions 17
Marc No More Yearly Quality Digest Registrar Rating? Registrars and Notified Bodies 3
Marc Quality Digest Coffee Break and Water Cooler Discussions 12
M Is That A Knife In My Back?!?! Quality Digest (February 2002) Misc. Quality Assurance and Business Systems Related Topics 40
D Quality plan for moving locations ISO 13485:2016 - Medical Device Quality Management Systems 3
was named killer Job Opportunity-Quality Engineer-Tampa Florida Job Openings, Consulting and Employment Opportunities 0
Marc Job Opportunity – Quality Assurance Specialist - Suspense 7 April 2021 Job Openings, Consulting and Employment Opportunities 0
C Requirement to link Quality Manual to ISO 9001 clause numbers? ISO 13485:2016 - Medical Device Quality Management Systems 13
normhowe "The Problem with Quality Management: Process orientation, controllability and zero-defect processes as modern myths" Book, Video, Blog and Web Site Reviews and Recommendations 2
J Quality Objective for QMS prior to Certification AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 8
J Quality Objectives and resources ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 11
M PSA Suppliers - CSR matrix and need the quality manual of PSA APQP and PPAP 2
A Quality Control Datasheets Inspection, Prints (Drawings), Testing, Sampling and Related Topics 0
T Quality auditor legal right to see Board meeting minutes ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 12
D Any recommendations on where to find experienced quality hires in Chicago area? Job Openings, Consulting and Employment Opportunities 3
C Budgetary cost to obtain ASME NQA-1 Quality Program Certification Quality Management System (QMS) Manuals 0
O Soft and technical skills for a VP of Quality Career and Occupation Discussions 1
P MedWatch Report from a hospital due to a quality issue US Food and Drug Administration (FDA) 5
Sidney Vianna Release of ISO 10013:2021, Quality management systems – Guidance for documented information Other ISO and International Standards and European Regulations 0
M Unique Quality Management System for 2 sites ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 5
G Application to Chartered Quality Institute - MCQI ASQ, ANAB, UKAS, IAF, IRCA, Exemplar Global and Related Organizations 2
K Quality Agreement MDR - The manufacturer is outside of EU Other Medical Device Related Standards 4
Sidney Vianna Informational APQP4Wind - Advanced Product Quality Planning for the Wind Power Supply Chain APQP and PPAP 3
T 21 CFR 820.20 - Quality Planning Requirements? 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 2
S Supplier protocol for the Quality Supplier Quality Assurance and other Supplier Issues 6
bruceian Software Quality Metrics Software Quality Assurance 11
R Quality System Functional Safety Checklist / Guidance IATF 16949 - Automotive Quality Systems Standard 0
Bev D Essential References for Practical Quality Engineering Misc. Quality Assurance and Business Systems Related Topics 0
optomist1 Automotive News The Cost of Inspecting In Quality IATF 16949 - Automotive Quality Systems Standard 7
O Any info on release date of FDA “Computer Software Assurance for Manufacturing and Quality System Software” document? 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 0
M Quality Manual - Where does Revision History Section go? Document Control Systems, Procedures, Forms and Templates 8
John Broomfield CIOB - Code of Quality Management Misc. Quality Assurance and Business Systems Related Topics 1
S Quality Audit Training Activities Quality Manager and Management Related Issues 2
D Are Supplier Quality Agreements Quality Records ? Other Medical Device Regulations World-Wide 9
D Big companies suffer from quality management system? ISO 13485:2016 - Medical Device Quality Management Systems 1
K Looking for a job as Quality Engineer Career and Occupation Discussions 2
B Two excellent examples of process capability analysis from Quality Magazine Capability, Accuracy and Stability - Processes, Machines, etc. 5
Pau Calvo Quality Management process is mandatory in ISO9001? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 10
NDesouza No Quality Professional vs Having a Quality Professional Benchmarking 24

Similar threads

Top Bottom