George,

>Why are you equating the cost of something, in this case a part, with the underlying quality? It either does what it's supposed to do or not.

This is not a black or white thing, i'm afraid. Often we don't know if a part meets the requirements. In particular in a market where there is a lot of inovation you can choose for a new product (with a unkknown quality) or a part with a known quality. If there is a substantial difference in costprice you can choose for the known quality or not.

You are saying that quality is simply 0 or 1; It does or does not meet the reqiurements. If this is true you can never have more quality if you already have quality.

Lets say that the requirement for one product is an average lifetime of a product must be AT LEAST 5 years. If Product1 has an avarage lifetime of 6 years and product2 has an avarage lifetime of 8 years, i would say that both these products meet their requirements but that product2 has more quality.

>If it does then it conforms to the requirements, if not, it doesn't. More expensive does not equate to higher quality. That's the point. Unfortunately, this is a common misconception.

I still think that you have a different interpretation for the word quality and requirements. Given your interpretation of the word quality I wonder what your interpretation of the word requirement is.

These day's car manufactures are capable of making a car which has an avarage lifetime of 20 years. But this makes the car so much more expensive than other cars. Both type of cars are build conform the requirements, because lifetime was not mentioned in the requirements.

Another example is that in the beginning of this century bridges where build by making use of rivets. These bridges were of very good quality (strong) because of metalurgic security factors, but were very expensive. But when they invented welding, they could make bridges of less quality (are not so strong) because the metalurgic factors are different for welding. So they had to choose, delivering quality or for the lowest price, though both type of bridges met the same reqiurements.

In the 2nd world war the quality of german tanks were much better than those of the allied forces, though they probately had the same requirements. The average German tank beat about 3,4 or 5 alied tanks. But the quality had it's price. the german tanks were not so easy to produce. Eventually the quantity of the allied tanks lead to the victory.

IOW to much quality can kill you !!!

Maybe you tell me where i did miss the boat.....

Walter,