Reliability is the probability that the product or service will perform its intended function for a specified length of time. Durability is defined as the length of time a product functions. Quality of conformance is a measure of how a product meets its specifications. For example, the specifications for a machined part may be a drilled hole that is three inches in diameter, plus or minus 1/8 inch. Parts falling within this range are defined as conforming parts. Fitness for use is the suitability of the product for carrying out its advertised functions. If there is a fundamental design flaw, the product may fail in the field even if it conforms to its specifications. Product recalls are frequently the result of fitness-for-use failures.
Improving quality, then, means improving one or more of the eight quality dimensions while maintaining performance on the remaining dimensions. Providing