Let’s talk quality: a short essay on this magic word

During all these years I have collaborated with hundreds of companies and worked side by side with countless people: machine operators, top managers, CEOs, or company presidents, and so on. Over almost half a century of professional activity, I noticed all these people had in common the pride and confidence that all products coming from their hands were of excellent quality. On more than one occasion, when I looked more closely at their artifacts, the impression I got was quite different. But since I was not in a position to judge, unless I was asked directly, I’d stay quiet.

So I imagined - years later - a hypothetical dialog with one of these people, with questions and answers on the theme of "quality". Because in truth, after having read, studied, attended courses, both as a student and as a speaker, in Italy and abroad, today I can say that these gentlemen, who so stubbornly defended the goodness of their work, were right.

"What is quality?"
If we are speaking of an object or service made specifically for a customer and having a specific task, "quality" means how and how well this object or service will succeed in meeting the set requirements.
If we're speaking of mass-produced objects or services intended for multiple uses or users, "quality" means how well this object or service will succeed in fulfilling the purpose it was designed for and the needs of everyone who uses it.
I've read and heard many definitions about quality, some fancier than others, but the one that sounded most fair to me reads, "The quality of a product means its ability to match the specifications for which it was designed and to meet the minimum requirements of the customer for whom it is intended."
So all my customers were right! Even when their products looked like junk to me, they really weren't, because they were regularly sold and used to their satisfaction; therefore they were "capable of meeting the minimum requirements demanded by the customers."

"Is quality based on skill?"
Yes, of course. If we were to make a single sample for a single customer, the cost would most definitely be high but of secondary importance, because the main goal here would be to make a product that meets the set aesthetic, technical, and functional prerogatives; in other words, a product complying with the customer’s demand.
If we were to mass-produce it in order to sell it on the market, it would have to satisfy the requests of many customers; therefore the cost would become relevant, and even more important would be its quality, which in this case is dependent on the skill to make products able to satisfy the minimum requirements of many customers equally.

"Is it even possible to make products that are all perfectly the same?"
No, it's not! No two things in the world are perfectly equal! There are things that look the same and even when measured they turn out to be the same, but they are actually NOT the same.

"But I measured them!"
True, but this happens simply because the instruments used cannot "see" the differences; if we measured the same things again with more precise instruments, we would find that there were actually differences between them.

"But are they just as good?"
Of course! The quality of a product is defined as its ability to meet the minimum requirements of the customer for whom it is intended. Mass-produced products must meet this condition while keeping differences within limits that do not affect their operation.

"How different can they be from each other?"
The allowed variations within which products are nonetheless defined as acceptable by customers are called "tolerances."

"But how do I know if my products are within the tolerance range and therefore acceptable?"
Dimensions and tolerances should always be defined in the design phase and then verified during production.

"How to verify them?"
There are two most commonly used control methods: by attributes and by variables.
Control by attributes is generally used to evaluate the visual and functional characteristics of a product (e.g., it’s good, it’s ugly, it's too wide, too narrow, it's great, not so great).
Control by variables is used when you want to know how much of a product is right or wrong. It is used both during production and on finished products. During production it allows you to know the accuracy of the production process. When used on the finished product, it will confirm the accuracy of the product itself.
Only by knowing the measured numerical values, it is possible to quantify the extent of variation in product characteristics and to know whether they fit the established tolerance limits.

One of the earliest statements by Lord William Thomson Kelvin (Belfast, 1824 - Largs, 1907), later taken up by Dr. W. Edwards Deming (Sioux City, 1900 - Washington DC, 1993), who is considered the father of the modern concept of quality, states:

“If you can not measure it, you can not improve it."

Mass production is controlled during processes so as to keep products in the "tolerance range" and also minimize variations or differences at an ever-lower cost.
Achieving this result is the real challenge today.

There are many techniques to do this, we will have our chance to deepen this subject.
Giovanni Stagni
Fasteners Consultant
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