Z
ero defects (ZD) is probably the simplest, most effective quality management concept ever conceived. Zero defects always works and it can’t fail—only the leader can fail. Once a leader accepts ZD as his or her personal performance standard, error will no longer be tolerated and defects will go away; defects will be prevented. When the leader weakens, ZD can falter. Even then, it doesn’t really fail. Like the old Army ballad “Old Soldiers Never Die,” it just fades away.
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Check out one of my previous articles in Quality Digest Daily, “The Magic Pill." You’ll learn that The Magic Pill is the realization that people perform to the standard that is set or accepted by their leader. If the leader’s performance standard is zero defects, people will perform to that standard. That’s why ZD works. Some say it’s impossible to produce defect-free work. If you can produce defect-free work some of the time, then you can produce defect-free work all of the time. No? Why not? If you don’t know how to produce defect-free work, ZD won’t help. You better call in a couple of Six Sigma Black Belts to work their problem-solving magic. Of course, if you’re always in the problem solving mode, you’ve already lost the game. If someone’s job is solving problems, they will never run out of problems. It’s like building a rework center in a factory; it’s always busy.
The ZD mantra is, “Do it right the first time.” It’s strange, but that idea has its detracters; can you imagine? If you search the web, you’ll find all kinds of silly arguments against zero defects. Some will say that you can’t reach perfection. Who said anything about perfection? Many software developers get panicky, and claim that zero defects can’t apply to them. Research-type people seem to feel the same way. The American Society for Quality, back when it was the American Society for Quality Control (ASQC), had a conniption when the American Society for Zero Defects (ASZD) was formed. They even published a proclamation in their magazine claiming that there was no need for such an organization, or ZD itself. In truth, there was a need for ASZD, and it’s too bad it disbanded. The ASQC treated ZD as a “motivational program” and assigned it to its motivation section, where it faded away.
There is no need to be ZD-phobic; it won’t hurt you. It doesn’t take a lot of courage for a leader to establish ZD as the performance standard. Software can be written right the first time. That doesn’t mean that errors won’t be made during development, but they can be corrected before the software is released to the customer. It’s like me writing this article. I make typos, or change my mind about the use of a word or a phrase. I’ll admit that software has a big opportunity for latent defects. I know from experience in developing my own statistical process control software. A defect in a program can be out there, used by hundreds of people for several years, and work just fine. Then, some guy puts in a comma instead of a decimal point and there's big trouble. I had that happen with my software. It was a simple thing to make a change to the software and update customers. Now we know what caused that error, it won’t happen again.
The same is true with research. I’ve heard researchers claim that failure is part of the process. Maybe so, but the work must be done correctly, with accepted procedures and methods. Edison went through thousands of filaments until he found the right one for the light bulb. Were these defects? I don’t think so, he didn’t do anything wrong. Anyway, it’s silly to even argue about it. If you're happy with things the way they are and don’t think that ZD applies to your work, don’t bother with it. But there’s no reason to preach about its evils.
I’ve had several discussions with a couple of doctors about the performance of their office staff and laboratory. If the lab makes an error, how can the doctor or the researcher make good decisions? A mistake in the office can cause all sorts of problems. A lab error could guarantee a bad diagnosis. Zero defects applies to software, research, medicine, teaching, manufacturing, flying airplanes, and everything else—ZD applies to all work.
The real beauty in zero defects is that it’s a simple concept and easy to implement. It starts when the leader sets a performance standard of zero defects. Unlike total quality management, Six Sigma, and programs of that ilk. The average employee doesn’t understand programs like those. I once checked into a hospital that had a Six Sigma program. I asked a nurse what Six Sigma meant. She said, “It’s something management’s doing.” The ZD performance standard applies to all types of work: engineering, purchasing, human resources, production, quality, clerical, maintenance, and many others, in fact, all others. It isn't just for manufacturing.
Everyone understands what zero means; everyone knows what a defect is. It’s infectious; people think about it. No expensive training, no Black Belts, no complicated procedures, no additional staff, yet it works. How can that be bad? Zero defects works if you build atomic bombs, make Subway sandwiches, publish a magazine, or make hardware for automobiles.
Whatever you do, it can be done right.
Comments
Zero defects
I don't think one will find many people who really object to the idea of doing things properly the first time. Alas - it's easier said than done due to the inherent fallibility of human thought, planning, and effort. A key problem with the zero defect approach as I have seen it applied is that it is often treated as a quasi-religious dogma, rather than a quality objective or methodology. Some processes (I suspect the VAST majority) are incapable of producing zero defects. They may produce VERY low levels of defective product, but not zero. Often times the cost involved in reaching zero is so high that it vastly outweighs the potential benefits.
I have had personal experience with a process that produced and leaked a rejectable part once every 4 to 6 months. That defect had no affect on safety or on the reliability of the final assembly, and was virtually invisible to the final user of the product. The part cost something like 25 cents. The cost to reliably detect each and every one of those would be tens of thousands of dollars, and a proper process redesign to get (maybe) to zero would cost 6 figures. There is no economic justification for pushing to zero defects in that case or the many similar cases out in the world at this time. Yet the customer for that product is baffled that anyone would be reluctant to dump adequate resources into the effort to go from very few bad parts to zero bad parts. After all, bad parts are morally repugnant. Defects = sin, and they make the angels cry. It's an absurd, legalistic mindset divorced from the reality of the economical production of goods.
Continual improvement efforts, focused on the biggest cost drivers, are the key to profitable allocation of scarce resources. Good engineers, technicians, maintenance men, machine operators, etc. are increasingly hard to find, and usually overworked. Zero-defect dogmatism threatens to disrupt the logical process of assigning priorities by giving it a moral dimension and the associated emotional preoccuption with things that are "wrong."
I fear we're doomed to live in a world that has a few defects now and then.
Zero Defects
I used to manage semiconductor packaging design and support engineering and was accosted one day in the 1980s by a young quality engineer full of Zero Defects zeal. He was concerned that the yield of the prototype runs of a brand new package construction and design was less than 100% (it was actually ~93%) and he was 'threatening' to shut down the production line start-up as a result. I politely told him that I would allow that if he would shut down the whole wafer fab. operation first.
He didn't, at first, understand my response so I pointed out that the semiconductor yields from silicon wafers had never been 100% and were never expected to be. Frequently the first wafers yielded zero yield and only the incredible 'microsurgery' techniques of a very gifted colleague managed to verify most of the problems and their resolution without costly and time-consuming complete new wafer run. The new wafer run would ratchet up yields to perhaps 10 - 20% if we were lucky, but that would be sufficient to initiate production runs. What was important was that, despite very much less than perfect yields from the current state-of-the art wafer yields, the business could be commercially viable, either immediately, or in the near future. Waiting until perfection had been achieved was untenable and ludicrous. The packaging technology was instrumental in enabling at least a two years advantage over the competition, on a breakthrough product line, because it resolved a series of problems that the mainstream industry packaging approach could not handle.
What do we learn from this anecdote?
I believe it is that, for relatively simple, deterministic, mature process systems (e.g. machined parts, software etc.), the zero defects target is a reasonable target that can be closely approached or achieved. However, for complex, less mature, non-deterministic processes (e.g. silicon wafer fab., or complex new productline production shakedown etc.) the ultimate 'target' should be 100%, but initially, realistic, intermediate, lower targets are commercially rational and essential.
Zero Defects
Zero defects can and is achieved in many ways throughout the manufacturing industry and service organizations. Granted there are some processes that yield less than 100% but zero defect performance is related to what is required by the customer. Most customers that I have communicated with do not want to pay for any defective products. They do not want to sort for defects or add any no-value added steps to their processes to deal with potential defects. Would you fly on a plane if 1 out of 10,000 landing gear assemblies contained a defective $0.25 part that may fail during landing? I think not. How many babies are doctors and nurses allowed to drop at birth? I would think zero. The point is that you set a performance standard and then look for cost effective ways to achieve results 100% of the time. Mistakes are made but you don't just say it is too costly to fix. If you don't do it, your competitors will.
Zero Process Defects But Not Zero Output Defects
I've worked in healthcare quality for nearly two decades (so including the TQM drive in the early 1990's). In hospital care, I think we can set a goal for zero process step defects, but we can never totally eliminate such defects as death, infections, certain complications, and the like.
As an example, a patient can get perfect care as defined by the current evidence based medicine with regard to thromboembolism prevention (e.g. the proper blood thinner such as lovenox, have surgical stockings, etc.) and still get a Deep Vein Thrombosus (DVT) or even worse a pulmonary embolism (PE) resulting in major morbidity if not death. Similar "perfect care processes" can occur in care for heart attack, pneumonia, stroke, etc., and there can still be negative outcomes including death. Even infections are often more related to patient condition (e.g. smoking, obese, diabetic patients have much higher infection risk) than to the processes of care.
In healthcare at least, to set a goal of zero output defects, becomes an empty exhortation by management (one of Deming's sins). On the other hand, we should set the bar at zero defects for process metrics (like hand washing, patient identification, following evidence based practice, etc.)
Steve Osborn, CSSBB, CPHQ
VP, Quality
Saint Vincent Health Center
Erie, PA
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