What is the conversion for PPM defects vs. Sigma Equivalents?

Statistical Steven

Statistician
Staff member
Super Moderator
#21
Bev D said:
and your point is? if it works who cares what you call it? I am seeing real statistical engineering quality improvements and control being enacted in numerous organizations under the name of six sigma that I never saw under process control or tqm...i'm just thrilled more people and organizations are actually using and embracing the techniques and systematically ingraining them into their organizations...I just dont get the visceral disdain around the term (seemingly bitter?)


I understand the disdain for the hacks (like Mikel Harry) who used good old american capitilism or snake oil salesmanship and made tons of money off the name gimmick - but these guys are always out there.
Bev, let me give you my $0.02 as to why six sigma is a sham. Call it bitter, because I am. I spent nearly 20 years as a professional statistician, CQE and quality improvement professional just to be told I am not qualified to be a six sigma black belt. I need to be blessed by some money making organization to learn tools I already have? I guess I just do not get it.
 
Elsmar Forum Sponsor
E

e006823

#22
Bev D said:
and your point is? if it works who cares what you call it? I am seeing real statistical engineering quality improvements and control being enacted in numerous organizations under the name of six sigma that I never saw under process control or tqm...i'm just thrilled more people and organizations are actually using and embracing the techniques and systematically ingraining them into their organizations...I just dont get the visceral disdain around the term (seemingly bitter?)


I understand the disdain for the hacks (like Mikel Harry) who used good old american capitilism or snake oil salesmanship and made tons of money off the name gimmick - but these guys are always out there.

Mikel Harry is a very divisive character with 6 Sigma practitioners. In my opinion his most significant contribution was the marketing of 6 Sigma. It gave the techniques credibility in the boardrooms due to the emphasis on savings and the bottom line.
 

Bev D

Heretical Statistician
Staff member
Super Moderator
#23
Statistical Steven said:
I spent nearly 20 years as a professional statistician, CQE and quality improvement professional just to be told I am not qualified to be a six sigma black belt. I need to be blessed by some money making organization to learn tools I already have? I guess I just do not get it.
Now that's a great answer! And I've been there. Back in the mid nineties I was 'doing' six sigma for Honda (although I didn't call it that because Honda likes to do their own thing). I started applying for master balck belt positions since I had a very strong training background and improvement project leadership/success rate. I was told by everyone that since I wasn't 'certified' by GE or Allied or Motorola then I wasn't qualified to be a MBB.. so I bit the bullet, held my nose and went to one of those 3 companies to become certified as a BB...worst 18 months of my life. their program was Mikel Harry joke right down to the powerpoint clip art handouts and the 1.5 sigma shift. As soon as I got thruthe program I was out of there. but I had my golden pass and my career took off in the direction I wanted it to.

But there always these types of artificial barriers - form teh 'need' for a certain 4 year degree to a speicifc experience, etc. the trick is how you manipulate around this and sell your experience and success as meetign and even exceeding the 'piece of paper'...
 
G

Gerula

#24
?

Hi everybody,

You might say anything you want about Mikel Harry (at the end of the day it's a matter of personal opinion) only that we have to keep in mind that usually a business is run to make profit. From this perspective, what Mikel did was to convince the owners/CEOs/CFOs and so on to start using inteligent tools when running their operations in a structured manner. Is he a salesman? Yes, he is. Is he taking advantage of this system? Yes, he is. But isn't this our society is all about? Yourselfs have said that you tried to sell your knowledge and you couldn't due to various reasons including not being a certified BB (to be honest, why a certification as QE is different than a BB? Both are commercial certification as you have to pay for and other than a certification body saying that you passed their certification criteria there is no guarantee of how the individual is going to perform in real life- wait a minute isn't this what school does too?). So, beyond the phylosophical discussions, as long as a system works it's up to the practitioneer to use those tools that are most suitable to the business they are part of. Do I sound too much like a cold bloded finance-ist? Yes, but take a look around you and see how the world functions lately, look at how many jobs are being lost to low cost countries. Is this a good time to polemize about systems and implementation methods and who makes money out of that? I say let's go back to discussing professional subjects and see how we can help each other progress in what we do every day.

Regards
 
R

ralphsulser

#25
Bev D said:
Now that's a great answer! And I've been there. Back in the mid nineties I was 'doing' six sigma for Honda (although I didn't call it that because Honda likes to do their own thing). I started applying for master balck belt positions since I had a very strong training background and improvement project leadership/success rate. I was told by everyone that since I wasn't 'certified' by GE or Allied or Motorola then I wasn't qualified to be a MBB.. so I bit the bullet, held my nose and went to one of those 3 companies to become certified as a BB...worst 18 months of my life. their program was Mikel Harry joke right down to the powerpoint clip art handouts and the 1.5 sigma shift. As soon as I got thruthe program I was out of there. but I had my golden pass and my career took off in the direction I wanted it to.

But there always these types of artificial barriers - form teh 'need' for a certain 4 year degree to a speicifc experience, etc. the trick is how you manipulate around this and sell your experience and success as meetign and even exceeding the 'piece of paper'...

:applause: Good for you Bev, I agree.
 
N

Narfeldt - 2011

#26
PPM vs Sigma level

I found a formula that I entered in excel.
You can see the formula in column B.
Hope this could help you.
 

Attachments

Tim Folkerts

Super Moderator
#27
Narfeldt,

That's a rather good approximation for converting between sigma levels and PPM. It seems to be good to within about 2% over the range of 2 sigma to 6 sigma.

Still, why not just use the "true" conversion?

=(1-NORMSDIST(A2-1.5))*1000000

Granted, calculators often don't have the inverse normal function built in, so then your equation

=EXP(-((A2-0.8406)^2-29.37)/2.221)

would be a handy alternative. But since Excel (and many other similar programs) can do the true function, we might as well use it there. The true version also lets you remove the 1.5 sigma shift if you so desire.


Tim F
 
P

Palt88

#28
Dear all, sorry to "undig" the post, but I have a little concern with some values.

Does someone is able to give me the real conversion of 4 sigma to Ppm? (with no 1.5sigma shift)

You will tell me "you already have an exemple upside".
The problem is that if we took this table:




ok 4 sigma gives 96ppm...

If I check another table:





ok...63ppm....


My statistical software gives me a 4 sigma up to little bit more than 32ppm.

My statistical software gives value with no 1.5 sigma shift, means that I found 4.5 sigma with 3.4ppm.

The 2 tables above gives 2700ppm for 3 sigma, as ma statistical software gives 1370ppm.

Then you can see for 2 sigma the 2 tables are different, 71860ppm - 45500ppm and around 23000ppm for my software...

:confused:

How to clarify that? it seems that for the 4.5 sigma at 3.4ppm everybody is ok, but do someone is able to explain why we can find so different things for other values?

Thanks
 

Tim Folkerts

Super Moderator
#29
The "traditional" calculation assumes teh process is centered and included both tails. The six sigma calculation assumes the process is shifted to one side, so it only includes the closer tail.

If you double the results you calculated, you will get the "traditional" result.

And it looks like the "96" value for 4 sigma is wrong -- it should be 63. I get 31.7 PPM for each tail, or 63.4 PPM for both tails.


Tim F
 
P

Palt88

#30
Thanks tim. :agree1:

I still have a doubt... because the result I got (32ppm) is the "Total ppm", as the addition of ppm on both side...
Would I really need to x2 the result from my statistical program?
 
Thread starter Similar threads Forum Replies Date
F Conversion of coordinate dimension holes to position dimension Design and Development of Products and Processes 3
D MDD to MDR - Technical File conversion EU Medical Device Regulations 4
S Class II to OTC conversion of a medical device 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 1
B How do you manage your project? Data Conversion and Digitization Records and Data - Quality, Legal and Other Evidence 9
Q Surface Roughness - Conversion of RS on a Print to RZ General Measurement Device and Calibration Topics 3
P Conversion of fraction to decimal for R&R of english ruler Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 8
P Effective way for DC/DC conversion for 2 MOPP @ 250VAC IEC 60601 - Medical Electrical Equipment Safety Standards Series 3
B Conversion and Rounding Standard for converting metric to english and vice versa Other ISO and International Standards and European Regulations 4
P IEC 60601-1-11 - Conversion to Double Insulation IEC 60601 - Medical Electrical Equipment Safety Standards Series 2
M Customer Conversion and Retention / Satisfaction Measurement Index Benchmarking 4
S Quality Objectives for Aerospace Chemical Conversion & other Surface Treatment Plant AS9100, IAQG 9100, Nadcap and related Aerospace Standards and Requirements 3
B QMS Conversion including Documentation and Understanding our Processes ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 3
R Preparation for AS9100B conversion to AS9100C AS9100, IAQG 9100, Nadcap and related Aerospace Standards and Requirements 5
S FSC Chain of Custody - Volume Control & Conversion Factors Various Other Specifications, Standards, and related Requirements 7
S Surface Finish - Conversion factor to transform Rz Jis in Rz Inspection, Prints (Drawings), Testing, Sampling and Related Topics 6
T Specification Conversion from Sets to Individual Measurements? Inspection, Prints (Drawings), Testing, Sampling and Related Topics 5
F Conversion from Agile - Need cheaper FDA compliant software Qualification and Validation (including 21 CFR Part 11) 7
C Conversion Help!! Print with this dimension .2917+/-.0005 :1 Inspection, Prints (Drawings), Testing, Sampling and Related Topics 9
kedarg6500 Unit Conversion Add-in for Excel Excel .xls Spreadsheet Templates and Tools 7
I Medical Device Directive, Conversion from class IIb to class III EU Medical Device Regulations 4
A CMM Software Conversion - Converting from Zeiss/Calypso to Brown & sharpe PCDMIS Inspection, Prints (Drawings), Testing, Sampling and Related Topics 7
K Micron to Inch Conversion Misc. Quality Assurance and Business Systems Related Topics 10
P Rockwell, Brinell, Vickers Conversion - Evaluating Aluminum 6061-T6 and 6063-T6 General Measurement Device and Calibration Topics 11
E Cost Savings based on 2005 Production - Metric Conversion Problem Misc. Quality Assurance and Business Systems Related Topics 4
Ron Rompen Conversion of surface finish measurements Inspection, Prints (Drawings), Testing, Sampling and Related Topics 4
Proud Liberal Microfinish conversion - Micrometers (?) to microinches? Manufacturing and Related Processes 3
Courier Conversion TO ISO9001:2000 / TS16949:2002E IATF 16949 - Automotive Quality Systems Standard 7
K Conversion from ISO 9001:1994 to ISO 13485:2003 ISO 13485:2016 - Medical Device Quality Management Systems 4
I ISO 9000:2000 Conversion Presentation Request ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 1
Marc Best 'Units' Conversion Web Site and/or Program Book, Video, Blog and Web Site Reviews and Recommendations 6
S Conversion from ISO 9001:1994 to 9001:2000 ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 3
M Targets / limits for PPM/ Scrap Manufacturing and Related Processes 2
M Internal PPM Manufacturing and Related Processes 1
A ISO 2859-1 - 9.3.3.2 Switching score - Sampling Plans and PPM AQL - Acceptable Quality Level 0
S Software for Supplier Charge back and internal PPM General Information Resources 2
L PPM - wrong parts or defective parts? IATF 16949 - Automotive Quality Systems Standard 18
0 PPM calculation of customer complaints for PMS Customer Complaints 10
F Determining what type of scrap to include in my internal PPM calculation Quality Manager and Management Related Issues 5
R PPM, Pictorial Process Mapping, Templates Manufacturing and Related Processes 5
V PPM - Internal PPM / External PPM Quality Manager and Management Related Issues 4
L PPM Defect Rate as a Performance Metric - Are there Flaws? Quality Manager and Management Related Issues 9
N Converting ETO Residual Limits from PPM to mg ISO 13485:2016 - Medical Device Quality Management Systems 6
J Internal PPM's in a medium sized metal stamping plant Quality Manager and Management Related Issues 6
S What is appropriate PPM level for a Plastic Injection Moulding Supplier Quality Tools, Improvement and Analysis 4
Q PPM - Filtering Defects out of calculation Quality Tools, Improvement and Analysis 5
M Is PPM a good metric for gathering companywide complaints ? Customer Complaints 2
L Oil Field Bearing Production PPM Standard Benchmarking 2
V How is PPM (Parts Per Million) Calculated? Inspection, Prints (Drawings), Testing, Sampling and Related Topics 4
L Help with concept of PPM in SPC Statistical Analysis Tools, Techniques and SPC 6
Z Predicting External PPM Capability from Internal PPM Capability, Accuracy and Stability - Processes, Machines, etc. 1
Similar threads


















































Top Bottom