| In my last article, I listed some of the most commonly | | | | process needs to be validated to demonstrate that it |
| used definitions of Quality. In this article, I will explain | | | | results in predictable and reproducible results in the |
| how some of these definitions have been used. | | | | end-use of the product. A new design or product |
| - Making it by the blueprint is one of the oldest | | | | needs to be validated under actual use conditions. |
| definitions. It sets a minimum standard for performance. | | | | - Our tort legal system provides for the theory of strict |
| In order for a part to be considered good, it must fall | | | | liability. The manufacturer of a product is strictly liable |
| within the dimensional tolerances specified. It is a good | | | | for the consequences of its use. It is no longer buyers |
| versus bad concept. This definition is a Quality Control | | | | beware, but now sellers must beware, as well. This |
| definition, it was meant to separate those units that | | | | means that it is no longer sufficient for the product be |
| needed to be rejected or reworked from the rest or | | | | fit for its intended use, but the manufacturer must also |
| good. Taguchi recognized that is not sufficient to be | | | | be concerned with any unintended negative |
| within the specification limits. As the product variation | | | | consequences that could occur by its use or misuse. |
| spreads away from the target, Taguchi taught us, the | | | | The reader may remember the multimillion dollar jury |
| costs to the company (rework, scrap) and society | | | | award to a consumer who was burned by an |
| (wasted resources) increases. Therefore, making it by | | | | extremely hot cup of coffee served by a fast food |
| the blueprint addresses the Customer needs, but only | | | | restaurant. A tire manufacturer has to be concerned |
| for the characteristics of the shipped product. It looks | | | | with the safety of its products, not only when the tire is |
| at Quality at the moment, but it fails to encourage | | | | properly inflated, but even when it is underinflated. The |
| product or process improvement. | | | | manufacturer must examine all predictable modes of |
| - Dr. Joseph Juran brought us the concept of Quality | | | | failure and look for ways of reducing such risks. |
| as the fitness for intended use. A product is only as | | | | Today, this risk abatement is also part of our definition |
| good as its performance in the intended application. By | | | | of Quality. |
| placing emphasis on the way the product will be used, | | | | So we have gone from doing exactly what has been |
| the producer will need to understand the needs of the | | | | defined on paper to trying to predict what else can go |
| Customer. The producer and customer must fully | | | | wrong! The reader must learn the Quality tools used |
| understand how the product will be used and how | | | | today to mitigate these risks. Tools, such as FMEA |
| various attributes of the product can affect that | | | | (Failure Mode and Effect Analysis, help us determine |
| performance. Aside from verifying that the process | | | | risks in our designs and processes. |
| results in meeting the specifications of the product, the | | | | |