The Elsmar Cove Business Standards Discussion Forums More Free Files Forum Discussion Thread Post Attachments Listing Elsmar Cove Discussion Forums Main Page
Welcome to what was The Original Cayman Cove Forums!
This thread is carried over and continued in the Current Elsmar Cove Forums

Search the Elsmar Cove!

Wooden Line
This is a "Frozen" Legacy Forum.
Most links on this page do NOT work.
Discussions since 2001 are HERE

Owl Line
The New Elsmar Cove Forums   The New Elsmar Cove Forums
  Statistical Techniques and 6 Sigma
  Exponential Distributions

Post New Topic  Post A Reply
profile | register | preferences | faq | search

UBBFriend: Email This Page to Someone! next newest topic | next oldest topic
Author Topic:   Exponential Distributions
TickTax
unregistered
posted 09 April 2001 02:30 PM           Edit/Delete Message   Reply w/Quote
I would be grateful for help with the following problem.

I know how to calculate DPMO for a Normally distributed process, but how do I calculate DPMO for an exponential distribution?

What DPMO figures do 3sigma, 4sigma, 5sigma and 6sigma processes produce?

IP: Logged

dWizard
Forum Contributor

Posts: 20
From:Normandy, TN 37360
Registered: Mar 2001

posted 10 April 2001 03:49 PM     Click Here to See the Profile for dWizard   Click Here to Email dWizard     Edit/Delete Message   Reply w/Quote
Basically, I ainât gotta clue. I have some more references at home I will check tonight, but I hold little hope. Try these links. Maybe they will help.

http://www.itl.nist.gov/div898/handbook/eda/section3/eda3667.htm

http://www.itl.nist.gov/div898/handbook/apr/section1/apr161.htm

Regards,
dWizard

------------------
I was better but I got over it.

IP: Logged

Rick Goodson
Forum Wizard

Posts: 102
From:Wuakesha, Wisconsin, USA
Registered: Aug 2000

posted 10 April 2001 04:50 PM     Click Here to See the Profile for Rick Goodson   Click Here to Email Rick Goodson     Edit/Delete Message   Reply w/Quote
I don't have a clue either but will take a look in some of my stat books. I am curious though, why do you need DPMO for an exponential distribution? What is the process your are trying to measure?

IP: Logged

Laura M
Forum Contributor

Posts: 299
From:Rochester, NY US
Registered: Aug 1999

posted 10 April 2001 10:53 PM     Click Here to See the Profile for Laura M   Click Here to Email Laura M     Edit/Delete Message   Reply w/Quote
It's late and its been a long day. But I'm thinking its the area under the curve from the point (spec limit?) to infinity. Which is the integral, isn't it?

Old brain cells are getting stirred up, but I once did the probability of getting a part out of a "leak spec." Leak distributions are typically exponential. Lots of 0's, and low values, a few creeping up to the spec. I was able to superimposed an "e to the x" distribution over real data. Then from the upper spec forward is the probability, convert to PPM. I excluded "major failures" because we were looking for those that were borderline and subject to measurement error.

I probably should have consulted books rather than shooting from the hip on this one, but you guys that did can correct me!

Laura

IP: Logged

TickTax
unregistered
posted 11 April 2001 01:26 PM           Edit/Delete Message   Reply w/Quote
Thanks to those of you who have responded so far.

Perhaps I should explain my problem a little more. I'm looking at a queuing process which has an exponential p.d.f. I am aware that for an exponential process with p.d.f lamda*exp(-lambta*t) the mean is 1/lambda and the variance is 1/(lambda^2) If I integrate from 4 sigma(mean plus 3sigma) to infinity (a 3sigma process?) I get 18316 DPMO. Other DPMO's calculated this way are as follows:

4 sigma - 6738
5 sigma - 2479
6 sigma - 912

However, Motorola's DPMO figures assume a mean which drifts +- 1.5 sigma. What I would like to be able to do is to calculate the figures assuming a similar drift in the mean of my exponential distribution.

IP: Logged

All times are Eastern Standard Time (USA)

next newest topic | next oldest topic

Administrative Options: Close Topic | Archive/Move | Delete Topic
Post New Topic  Post A Reply Hop to:

Contact Us | The Elsmar Cove Home Page

Your Input Into These Forums Is Appreciated! Thanks!


Main Site Search
Y'All Come Back Now, Ya Hear?
Powered by FreeBSD!Made With A Mac!Powered by Apache!