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Is It Clean? - Particles - A Word (or two) About Specifications


Before we get into quantifying the particles we have harvested in the last few blogs, I would like to take a minute or two to talk about the specifications that define and govern the evaluation process.  In upcoming blogs we will talk about the quantification of particles in general terms.  In real life, there is usually a specification defining this process. There are some standard specifications available that define procedures to be used for collecting and evaluating particles as a measure of cleanliness.  These specifications are published by a number of societies and organizations and, although useful as guides, are often not a "perfect fit" for every cleanliness evaluation requirement.  As a result, there are a proliferation of both industry specific and internal company specific specifications which have been developed to meet the cleanliness evaluation needs in individual cases.  Although these tailored specifications are well-meaning, many of them read like more like examples supporting the old adage

"A CAMEL is a HORSE designed by a COMMITTEE!"

Now hold on!  Before going "postal,"  I didn't say they were useless and I didn't say they were wrong, just that the intent of many of them could be met more concisely if the were conceived with a little more "common sense" approach. If you are faced with a requirement to develop an internal procedure for evaluating cleanliness the following DOs and DON'Ts may be helpful. DO study published cleanliness specifications as examples and a learning experience.  The purpose here is to condition the thought process and develop some familiarity with the terms and typical procedures used in cleanliness testing. DO start with a blank piece of paper.  If your requirement is special enough that you feel a tailored specification is required or justified, then it is different enough to be worthy of your effort to develop a good specification from scratch. DO think seriously about your cleanliness requirements.  What things are important and what things aren't?  What makes yours a special case?  What is the purpose of this specification. DO be specific enough to minimize the opportunity for "interpretation" or, more likely, "mis-interpretation."  If it is important that a procedure be done in a specific way, explain why. DO anticipate special cases.  Is the specification good for everything you do or do some things reqire a different specification?  Thinking about this ahead of time can prevent major issues at the time of implementation. DON'T try to keep up with the Jones's.  Just because a specification is used by NASA, one of the major automobile or aircraft manufacturers or any other respected entity does not mean that specification is right for YOUR need.  Remember, the people who wrote those specifications (hopefully) took the time to define their needs. DON'T try to "adapt" an existing specification (internal or external) with markups, insertions and deletions.  In this case, the HORSE mentioned above may turn into a HIPPOPOTAMUS.  Use existing specifications as examples, not "templates." DON'T write a book.  An overly complex specification won't be followed or understood.  There aren't many applications that require a document more than 4 typewritten pages in length.  If a longer specification is truly justified, make sure to include a "Readers Digest" version for those who don't have the time or interest to read the whole thing. DON'T develop a specification in an "ivory tower."  Involve the people who will have to follow and apply the specification in its development.  A committee comprised of the right people will result in that HORSE turn out looking more like a HORSE than a HIPPO. In summary - Am I "venting?"  Well, maybe a little.  But I have seen way too many cleanliness specifications that, although well-meaning, have led to unnecessary expense and confusion without really accomplishing their intended goal.  A good cleanliness specification should be the foundation of a cleaning process, not something written to control or evaluate an existing cleaning process.  Cleanliness can not be "legislated."

-  FJF  -