Correction line 5 shall be : aquisition, they can NOT accept such ... sorry On 7 July 2016 at 17:05, Inge Hernefjord <[log in to unmask]> wrote: > Well, I'm not much of the adviser I once was, so the question is if you > should read this. > > - You've already answered yourself when you ask for the level of a minor > deviation,which doesn't have a dentrimental effect on the process, and > ditto about a major deviation. Practical experience will give the level > individually for each process. > > - In fact, the two parameters 'minor' and 'major' are not of interest in > programming point of view, because the machines that sample and do the > data aquisition, they can accept such arguments as 'minor' and 'major' , > because they want mathematic useful levels, e.g. so and so many > milliamperes or nn % or other expressions..So, I would skip the whole > question and give the processing computer values that counts. > > - There is a area that has the most advanced processing of all, namely the > semiconductor processing. The sharpest brains arfe involved and there you > have the answers on practically everything you want to know..One reference > that I used to read is Dimitri Kececioglu and Feng-Bin Sun's wwork ' > QUANTIFICATION and OPTIMIZATION OF BURN-iN TESTING. isbn 0-43-324211-0. > Editid and printed by Prentice Hall, Upper Saddle River, NJ 07458. > Examples on content > > Chaper 4: Obsevations and the physical insight of the failure process > Chapter 5: Math Models Describing the Failure Process during Burn-In and > the Parametres Estimation. > > - What more to say is that your question is more or less difficult to > quantify, because of the complexity of the actual process. If yoy ask for > a simple process, let's say the manufacturing of a general purpose, cheap > resistor with the tolerance of +/- 10 %, you have only one proceessto keep > an eye upon, the laser trimming. If the you use modern trimmers, the > outgoiing tolerance is probably much better for Sigma 1-3, while Sigma 6 > represents only a few + 10% or .10 % per each one million batch. That > means that a deviation from normal +/. 2 % to new value l.et's say +/- 5 > % is not causing any problems. > > Making a car, for instance, is so complex and holds so many parameters > (thousands) that you need aqusite data for hundreds of cars before you get > experience of what deviations are acceptable or not. So, take into > consideration the complexity of the process you are asking for. > > My 2 p +/- 0.05 p > > /Inge > > PS. Think your younger and fresher (?) mate Dave got a lot to say. > > > > On 30 May 2016 at 01:54, Yuan-chia Joyce Koo <[log in to unmask]> wrote: > >> hopefully, it is not voting system. otherwise, you get vote out to the >> lowest std. (one system designer, with many part vendor, supplier, >> marketing guys, bean counters, etc. the program mgr will get over powered >> sometimes... horrible). >> jk >> >> On May 29, 2016, at 2:19 PM, Richard Kraszewski wrote: >> >> I would suggest the use of a pFMEA or dFMEA to assist in making that >>> decision. >>> Need to have all stakeholders involved in that exercise. >>> (yes I know this can be pain) >>> >>> Rich Kraszewski >>> (920) 969-6075 >>> >>> >>> -----Original Message----- >>> From: TechNet [mailto:[log in to unmask]] On Behalf Of Douglas Pauls >>> Sent: Thursday, May 26, 2016 10:00 AM >>> To: [log in to unmask] >>> Subject: [TN] How much change is change? >>> >>> Good morning all, >>> >>> One of the IPC groups that I am leading is presently wrestling with the >>> issue of minor vs. major change. Generally along the lines that if you >>> have a baselined or qualified manufacturing process, how much can that >>> process change before it needs to be re-baselined or re-qualified? >>> Sometimes this is referred to as Level 1 vs. Level 2 change. >>> >>> So far, every quality documentation system that I have looked at, like >>> AS9100, ISO9000, etc., gets really fuzzy and uses vague terms when you >>> approach this issue. Most of these documentation systems have change >>> better defined for products, but get extremely fuzzy and extremely vague >>> about manufacturing processes. >>> >>> This forum has a lot of very smart, very experienced people. How would >>> you differentiate a minor change, which would not impact form fit or >>> function, from a major change, which "could/would" impact form fit or >>> function? >>> >>> And I want all you lurkers to come out of the woodwork on this one. >>> >>> Doug Pauls >>> Principal Materials and Process Engineer Rockwell Collins >>> >>> >>> ______________________________________________________________________ >>> This email has been scanned by the Symantec Email Security.cloud service. >>> For more information please contact helpdesk at x2960 or >>> [log in to unmask] >>> ______________________________________________________________________ >>> >>> ______________________________________________________________________ >>> This email has been scanned by the Symantec Email Security.cloud service. >>> For more information please contact helpdesk at x2960 or >>> [log in to unmask] >>> ______________________________________________________________________ >>> >> >> >> ______________________________________________________________________ >> This email has been scanned by the Symantec Email Security.cloud service. >> For more information please contact helpdesk at x2960 or >> [log in to unmask] >> > >