David Garvin of the Harvard Business School developed a system of thinking about quality of products (some are applicable as well to services, but more on that in another post). Following is a summary of his eight dimensions of quality, as reported in Tenner & DeToro's book Total Quality Management.
Eight Dimensions of Quality
"...David Garvin has defined eight dimensions that can be used at a strategic level to analyze quality characteristics. Some of the dimensions are mutually reinforcing, whereas others are not--improvement in one may be at the expense of others. Understanding the trade-offs desired by customers among these dimensions can help build a competitive advantage. Garvin's eight dimensions can be summarized as follows:
1. Performance: The product's primary operating characteristic. For example, performance of an automobile includes traits such as acceleration, handling, cruising speed, and comfort; performance of an airline includes on-time arrival.
2. Features: Secondary aspects of performance. These are the "bells and whistles" that supplement the basic functions. Examples include free drinks on planes and sunroofs; on cars. The line separating primary performance characteristics from secondary features is often difficult to draw. Further, customers define value in terms of flexibility and their ability to select among available features, as well as the quality of those features.
3. Reliability: Probability of successfully performing a specified function for a specified period of time under specified conditions. Reliability of durable goods is often measured as the mean time to first failure or mean time between failures. These measures, however, require a product to be in use for a specified period of time and are not relevant in the case of products and services that are consumed instantly.
4. Conformance: Degree to which a product's design and operating characteristics meet established standards. Although this is some-times defined as "conformance to requirements," a sounder analysis will be obtained by examining each characteristic's divergence from its target value. This more robust measure of conformance is built on the teachings of a prize-winning Japanese statistician Genichi Taguchi.
5. Durability: A measure of product life. Durability can be defined as the amount of use obtained from a product before it deteriorates to the point that replacement is preferred over repair. Durability is closely linked to both reliability and serviceability. Consumers weigh the expected costs of future repairs against the investment in and operating expenses of a newer, more reliable model.
6. Serviceability: The speed, courtesy, competence, and ease of repair. The cost of repairs includes more than the simple out-of-pocket costs. Serviceability covers this full dimension by recognizing the loss and inconvenience due to downtime of equipment, the nature of dealings with service personnel, and the frequency with which repairs fail to correct the outstanding problems.
7. Aesthetics: How a product looks, feels, sounds, tastes, or smells. Aesthetics is largely a matter of personal judgment and a reflection of individual preference; it is a highly subjective dimension.
8. Perceived Quality: Reputation. Consumers do not always have complete information about a product's or service's attributes; indirect measures or perceived quality may be their only basis for comparing brands..."
-Tenner & DeToro, Total Quality Management