In the weeks leading up to American Thanksgiving and the rest of the holiday season, I found myself buried in a couple of projects related to the release of GainSeeker Suite, Version 8; and a course in Appreciative Inquiry. In the process, I got out of the blogging groove. (Version 8 is pretty cool. It includes some brand new modules that will help you get more value from your data, and make it even easier to use. More on the new version in subsequent posts. Likewise, I’ll write more about my interest in Appreciative Inquiry in the weeks and months to come.)

Now my editor at Quality Magazine is prodding me, so it is about time to get back in the rhythm, even though I still have some tasks on Version 8.

My last post at Quality Magazine on ‘Defining Quality’ (which was a revision of What are they thinking…?’ published here) generated a number of thoughtful comments from readers. I really appreciate hearing other perspectives on the questions I posed in the post, especially this comment:

Only in the world of utopia are there processes with zero variation and where only Green or on target values are produced. In the real world you have to look at each process and determine the ability and cost required to reduce process variability. In some cases it may be more cost effective to use an inspection system (like a vision system) to inspect out defects, then it would be to reduce the variation that creates these defects. The rule I use is if prevention is not practical and if detection methods are effective and reliable, then the inspection method is the right choice. When detection is difficult or not reliable, then prevention efforts must be taken.

This got me thinking about a model for inspection that I’ve found helpful in recent years. Here it is:

Bear with me because this graphic still needs some explanation.

If you look at this carefully, you’ll see that it is a typical ‘Input – Process – Output’ diagram. If you look at it even more carefully you’ll see that it is there are two loops on the graphic. The question isn’t so much which loop is right and which is wrong. The question is: Which loop is primary? Which loop is emphasized?

Both loops start in the middle with an observation or a measurement. The right-hand loop is the Voice of the Customer. I’ve highlighted it here in yellow:

The right-hand loop compares the observation to the customer’s requirements and asks “Does this meet the customer’s requirements?” If it passes, you can ship the product. If it doesn’t, you have a couple of options.

If your product fails to meet specs in a manufacturing environment, your options are to Scrap, Rework or Downgrade the product. In a transactional world, your options are to Remediate, Replace, or Compensate. In either situation your options for response are always reactive and wasteful.

I see people tolerate this waste for all kinds of reasons. Perhaps there are other, more expensive issues that need to be addressed before this problem can be tackled. Perhaps the cost of getting rid of a problem seems too high. Perhaps they’re just used to it and can’t imagine any other way of doing business. Some of these reasons are probably better than others, and I’m really not here to pass judgment in this blog. The point that I want to be clear about is that the right hand loop – the Voice of the Customer Loop – captures waste and protects the customer. There is nothing wrong with that (actually there are some good things about it). But it doesn’t prevent the problems from recurring.

The left hand loop starts at the same place, but has a very different impact. This is the Voice of the Process Loop, highlighted here in green:

The Voice of the Process Loop also requires an observation or a measurement, but here is the crucial difference. Where the Voice of Customer Loop compared the observation against specifications, the Voice of the Process Loop compares the observation against what is expected.

On what do we base our expectations? Well you can guess that it isn’t a specification – or anything that is derived from a specification or a requirement.

We base our expectations on our past experience with the process. This is why we call it the Voice of the Process. The best way to tap into our past experience with the process is with the humble control chart.

The control chart tells us what we need to know about the process. If the data we observe shows no patterns, no shifts in mean, and no more variation than we’ve experienced before, then we have reason to conclude that the process is stable. Once we know the process is stable, then we can still ask ourselves “is there a way to improve (reduce) chronic variation? This can lead to improvements in the process or the inputs to the process.

If the process tells us that it isn’t stable, then we can (and should) address that. We can focus our efforts on improving the process or the inputs to the process.

Using the left-hand loop – the Voice of the Process Loop – is how you improve processes and ultimately reduce or even eliminate the need for the Voice of Customer Loop. In an ideal world our processes are well understood and stable, and we don’t need to check against specs because we know that we’ll always meet customer requirements.

In the meantime, we live in the real world. In the real world, inspections against specifications are a reality and will probably be around for a long time. They’re useful and I would be the last to advocate their complete elimination.

But they don’t lead to process or quality improvement, or to an elimination of the waste associated with failure to meet requirements. To get there you need to pay attention to the Voice of the Process. You need to stabilize your processes and then systematically reduce chronic variation.

Where is your emphasis? Which loop do you follow? What are the biggest challenges you face or have faced in shifting your emphasis to the Voice of the Process Loop? Use the ShareThis button below to mark this page, leave a comment, tweet me, schedule a conversation, or call 800-958-2709.


  1. The Data Heads » Blog Archive » Emphasis - Page 2… February 16, 2010 at 4:07 pm

    […] The Data Heads « Emphasis…? […]

  2. The Data Heads » Blog Archive » Quality Mag post… February 22, 2010 at 10:30 am

    […] Quality Magazine picked up my blog post on the Voice of the Process loop. I’m really interested in your comments on the questions posed in the post, either at the Quality Mag site, or here. […]

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