This article is one in a series about customer-supplier principles for industrial and commercial purchasing relationships.  

© 2000 Corporate Training Partners, Inc. 

Customer-Supplier Principle  #6.

Avoid creating a "percentage defect allowance."

Good suppliers don't knowingly provide defective products. They know that defects are preventable. They know that defects are a problem, not a fate.  They know that employees should not be encouraged in advance to make defects.  

Last century, a misguided philosophy emerged called "Acceptable Quality Level."  It came from a misunderstanding of sampling plans.  "AQL" philosophers said that of every hundred units of product, one or two MUST be defective!  

The "AQL" idea demoralized employees, lost customers, and fostered lawsuits.  Management set a bad expectation, and encouraged employees in advance to make defects!  

There are no laws of physics that say all kinds of defects have to happen all the time.  The statement that "a certain percentage must always be defective" is simply not true.

Modern suppliers use product-sampling as part of a balanced effort.  When they use sampling plans, they use plans called "accept on zero," which means they write up a reject on the first bad unit in the sample.

• Example: The supplier instructs all employees to set aside any believed-to-be-defective units for disposition.  The supplier uses "accept on zero" sampling plans (technically called "c = 0" sampling plans).  The result is that no one is encouraging the production and shipment of known defects.

• Situation to avoid: Your supplier disagrees with one of your customer rejections, and decides to get even by "blending" the defective units, a few at a time, into future shipments. The supplier says, "Everybody knows there is going to be that 1or 2 percent defective, it's a law of nature!  It's standard in our industry that you get a 1 or 2 percent entitlement to ship defects. Everybody knows you can't be perfect, so why try? Everybody knows it costs way too much to go after that last 1%, so we're entitled to ship it to the customer.  If you make us sort the product we're going to charge you big extra money, buddy -- and of course, our sorting won't be effective anyway, so you'll still get the defects anyhow!"

• Question to ask: "What policies and instructions do you have in place to avoid accepting known defects, or accidentally or deliberately mixing defective units in with good units?"

Incredibly, there still exist suppliers who will start arguing in favor of defects before the ink is dry on the contract!  Avoid these suppliers!

In consumer transactions, the perverse "nobody is perfect" philosophy knows no bounds:

• "There is no such thing as a car that doesn't leak fluid."

• "Every piece of concrete is going to have cracks in it."

• "It's impossible to paint without missing some spots."

• "Nobody can guarantee any medical procedure, no matter how minor and routine."

The critical distinction is between some abstract notion of infinite perfection (which is best left to philosophers), and completing a finite task as promised (which has proven entirely feasible).  Don't let anybody bully you with irrelevant philosophy!