Know your limits
I read with interest your consultant's answer to the process improvement question (Expert Answers, January 2008, p. 10), and it's way too complicated.
The answer is that the process capability (plus or minus 8 sigma) of any process should be within the specification limits because if it isn't, you will be reworking or throwing away product.
If there are no specification limits, then there should be limits everyone involved in the process accepts. If not, no one will accept the reason behind improving the process. At that point, the process must be adjusted to fall within those specification limits. Sometimes, the process average should equal the specification average. This is the easiest way to make sure your process will make product correctly.
Forget about math and ratios, and just make sure you have a specification limit that will result in a quality product that is assembled correctly and does what it is meant to do. If your process capability doesn't fall within those limits, others will agree with your assessment to change the process.
Mr. Pareto Head is a cartoon (obviously), and it is amusing-to-funny. But it is a cartoon in QP, so one would at least hope for accuracy—if not for its own merit, then at least for the sake of all the anal-retentives (the majority?) among the professional readership.
In the February 2008 strip (p. 17), mean time between boyfriends (MTBB) would most accurately describe the periods when the girlfriend was without companionship. I think mean time to breakup (MTTB) would be more appropriate.
But, heck, if you have to explain it, it isn't as funny.
San Jose, CA
Solid points taken in the 3.4 per Million column, "Forget Silver Bullets and Instant Pudding," (January 2008, p. 72). There are no silver bullets for all types and sizes of game, just as the shot approaches must be different.
I find it fascinating that managers fail to take into account how assets are utilized and that the product types expected from those assets impact the effectiveness of any quality improvement effort.
Tell me what metrics senior managers have focused on, and I can usually tell you if there are problems to be faced. Behavior is always a function of metrics, and metrics are a function of leadership values. The problem lies in the reality of leadership wants, which are in conflict with each other, and the choices made to try and sort that out.
In the end, something has to give, and that's when managers start to believe in silver bullets.
-Posted at www.qualityprogress.com
Michael J. Orr