EVOP - Evolutionary Operation of Processes

[Marc]

An FYI thread:

--> From: Guy Rodgers - Subject: RE: EVOP -
--> Evolutionary Operation of Processes
--> Any experience/Mullins/Rodgers
-->
--> Mullins wrote; "Does anyone have any information on a course
--> called "Evolutionary Operation of Processes (EVOP)" which is
--> referenced in QS-9000, section II.2- Continuous Improvement?"
-->
--> The requirement for EVOP knowledge in Section 2.3 Techniques
--> for Continuous Improvement has been removed from the 3rd
--> edition Quality System Requirements of QS-9000. The section
--> has been moved to Element 4.2 Quality System under paragraph
--> 4.2.5.3.
-->
--> Other techniques eliminated from the requirement include;
--> Capability Indices (Cp,Cpk), Cost of Quality, and Problem
--> Solving. Finally, a note for interpretation was added to
--> clarify that the list only shows examples and other methods,
--> which meet the suppliers needs, may be used.
-->
--> To further explain, EVOP is not a course, but rather a
--> process or technique of systematic experimentation.
--> Evolutionary Operations (EVOP) is based on the understanding
--> that every production lot has the ability to contribute
--> valuable information on the effect of process variables on a
--> particular product characteristic or feature.
-->
--> Typical methods used involve structured designs of
--> experiments (DOE) which may result in interrupting production
--> flow to conduct the trials or experiments. EVOP, on the other
--> hand, is intended to introduce small changes in the process
--> variables during normal production flow. These changes are
--> not large enough to result in non-conforming product, but are
--> significant enough to determine the optimum process ranges.
-->
--> Best regards,
-->
--> Guy Rodgers, QA Administrator Paulo Products Company

Subject: RE: EVOP - Any experience/Mullins/Brauer

Sheila Mullins asks -- Does anyone have any information on a course called "Evolutionary Operation of Processes (EVOP)" which is referenced in QS-9000, section II.2- Continuous Improvement?

Reply -------------------------

While I cannot recommend a "course", you will find information on EVOP in statistics books on experimental designs. Look for one that has Response Surface Methodology in it. Here's a brief description of EVOP from one such book --

EVOP consists of systematically introducing small changes in the levels of operating variables, usually 2^k factorial designs, such that serious disturbances in yield, quality or quantity will not occur, yet large enough that potential improvements will eventually be discovered.

-- Design and Analysis of Experiments, 3rd Edition
-- by D.C. Montgomery, 1991, John Wiley & Sons, Inc.
-- ISBN 0-471-52000-4

Also, you should note that in QS 3rd Edition, Continuous Improvement is now 4.2.5 and EVOP was deleted from the examples list. However, I believe it would still be acceptable to use EVOP since it is a type of DOE (Design of Experiments) which remains on the examples list.

NOTE: Introduced in the 1950s by George Box, EVOP is an ongoing mode of using an operating full-scale process, so that information on how to improve the process is generated from a simple experimental design while production is underway. To avoid appreciable changes in the characteristics of the product, only small changes are made in the levels of the process variables. EVOP is designed to be run by process operators on a full-scale manufacturing process while it continues to produce satisfactory products.

EVOP is a tool in which a continuous investigative routine becomes the basic mode of operation for the plant and replaces normal static operation.

Hope this helps.

Les B.

[Marc]

>> "Greg House"
>> wrote in message
>> news:3bcc8c5c$0$227$cc9e4d1f...
>>
>> I have heard of most things in QA and CIP, but what is EVOP?
*****************

EVOP stands for "EVolutionary OPeration". Basically, it is a process (mainly manufacturing) improvement method developed by Box in de '50s. In this method, the process control variables (e.g. machine speed, temp, etc.) are continuously and systematically modified, the effect of these perturbations on the process output is monitored and the conditions when output is improved are noted. IMHO a combination of experimental design and SPC.

Jean-Philippe Hubin
*******************

"LamarJL" wrote in message news:JoJz7.12110$B82.3776493699...
> Howdy Greg,
>
> EVOP stands for EVolutionary OPerations. The concept was also commonly
> referred to as the "string of pearls" approach to finding the sweet spot.
> Using EVOP you make a change to your process, if the change was good then
> you keep going in that direction. If the change was bad you backed up and
> went the other way. Like the myth of biological evolution - it would take
> forever to find the best spot for each process parameter and you would
> completely miss any interactions between parameters. EVOP gave way to DOE
> and Taguchi style experimentation years ago.
>
> Regards,
>
> Jim Lamar, CQE, CQA, QS-LA, MQM, ABC, Do-Re-Mi, 1-2-3, yada, yada, yada,

EVOP is a special application of DOE so it can't be said to replace it. It is often a 2 level, 2 factor factorial.

The whole idea is that it is done with a running process so you have to keep the changes to the independent variables small so the the output variable stays in spec.

You can't optimize a full-scale production process except by running it, unless in the unlikely case that you know in advance that a small scale or pilot run exactly represents full scale production.

It can certainly take a while to run enough replications to extract the significance of the variables and their optima, but what's the alternative? You can certainly find the interactions. I know there are at least 3 approaches to analyzing the data. One method uses ranking but I have never used it. Maybe that doesn't show the interactions.

Regards,

John Duffus
###########
Some old EVOP messages are Here in case anyone is interested.

Anyone here doing any EVOP experiments?

From: Suzanne Fiorino
Subject: RE: EVOP - Any experience/Mullins/Bigelow/Fiorino

One can think of EVOP as 'baby steps" experimentation. Typically a small full factorial design is used to set up the EVOP test and the intent is to get meaningful information while still producing saleable product. QualPro in Knoxville, TN, has an excellent experimental design course, very practical, and a section of it covers EVOP. Also George Box, who is at the University of Wisconsin, may have a course on EVOP.

From: David Thibault
Subject: Re: EVOP - Any experience/Mullins/Thibault

One point not mentioned so far: Since the changes for EVOP are small relative to those for DOE, EVOP must rely on many replications to separate the signal from the noise.

Date: Sun, 23 May 1999 12:00:56 -0400
Subject: Electronic reprint of textbook about quality improvement using simplex EVOP

The textbook "Sequential Simplex Optimization: A technique for Improving Quality and Productivity in Research, Development, and Manufacturing" by F. H. Walters et al has been out of print for some time. CRC Press LLC has now licensed us t he right to make electronic reprints of this excellent text. We wish to continu e the work to popularize the simplex EVOP methodology, and make it an everyday tool for many more professionals and researchers. We have therefore decided to publish and distribute the electronic reprint through our web site. You may fre ely browse the whole text as HTML or download it as an Adobe Acrobat PDF-file from Grabitech.com

Best regards,
Tomas Oberg
MultiSimplex AB

[Sam]

And you can always check out the always faithful "Juran Handbook".

[Marc]

You know - I never looked in Juran's tome for it before.... Now I see it is discussed in some length.

[Kevin Mader]

Picking it up (literally) is an experience you will probably never forget!! Darned thing is big and heavy!!

[Marc]

Definition of tome
*
Part of Speech * noun

Definition 1. a large thick book, often one of a multivolume scholarly work.

I'll admit I don't see a weight specification, and I admit it's not technically multi-volume (note the qualifying word often in the definition which preceeds "...one of a multivolume..."), but I sorta was alluding to its heft - so to speak - calling it a tome. (Al: Actually I was just showing off my great vocabulary having been raised on Scrabble...)

I can't state it's bias, linearity, calibration to a reference standard or anything else fancy, but my bathroom scale indicates about 6 to 6.5 pounds (maybe one of our English compatriots here will translate that into stones for us).

One of you folks have a calibrated scale close by - How much DOES the book weigh? Do let us know which revision level it is... And the uncertainty of the scale... Etc...

[Kevin Mader]

A Scrabble Master - I am in awe!!!

On my SAT, I ranked in the 37 percentile in vocabulary. I was much better at Trivial Pursuit!!

Kev

[Marc]

My mother and little sister are the Scrabble Masters... They still play. It's their common ground, if you will.