Sunday, 10 April 2011

Thoughts on Quality

I wrote the following for a course in Quality Management:
Which philosophy do I prefer?  I suppose that at first glance I would prefer the academic rigor of Robert Pirsig but comments like “It (Quality) is the origin of heaven and earth, when named it is the mother of all things...” (pg. 227,  Zen and the Art of Motorcycle Maintenance) won’t get you very far on a Q.M. career path. I would rather end up as a tenured professor like some of the other gurus than in a psychiatric ward with electroshock therapy like Pirsig.  I also noticed that Laurence J. Peter who wrote The Peter Principle wasn’t on the list of gurus but I suspect that he would be a bit of a downer for the author of the article
True story:
My oldest daughter contracted Hep C from a blood transfusion when she was born.  Each year she was tested for ALT (a liver enzyme) to determine the progress of the disease and I was given the results of the test by the attending physician. One year the doctor told me that there was progression in the disease because of a slight increase in the value of ALT.  I pointed out that the year to year change was within the variability of the method not to mention the biological variation so the facts didn’t support the assertion. I didn’t get much traction with the physician.
As a level one quality – accuracy, imprecision and timeliness – I suppose it had quality but for me the quality in terms of accuracy of interpretation was lacking. For this reason, I would not consider purely quantifiable definitions like Crosby. Deciding between the remaining gurus is a bit more problematic. I think that any discussion of quality has to be done in the context of finite resources. In the 90’s I remember reading an article in Clinical Chemistry where the author did a study in which  there was an irreducible laboratory error rate of 3% and today we talk about six sigma (a quality assurance methodology) where the bar is three errors per million transactions. The point is that in my experience as we decrease the error rate the cost of the next iteration increases exponentially although I have read many articles about cost savings and I am open to counter arguments.
In conclusion, I’m not sure that Taguchi’s position is the best with his societal loss function.  “Quality is the loss a product causes to society after being shipped.” A good example of this is General Motor’s death rate/cost benefit ratio which it used in the eighties. The company did a quality analysis based on the ratio of the cost of fixing a defect component to the incremental increase in the number of deaths of passengers in the vehicles. Obviously from the manufacture’s point of view this is a level one quality issue while from the consumer’s point of view the preferred quality point is quite different.  I will error on the side of Juran’s “fitness for use.”

Hey I found the crack!
So what gives with fukushima? According to one source, an electrical panel controlling the safety pumps  hadn't been inspected in eleven years! The Japanese are supposed to be the world's leaders in Quality Assurance but they really screwed up.

No comments:

Post a Comment