What is Quality?

In Webster's dictionary, quality is defined as "the essential character of something, an inherent or distinguishing character, degree, or grade of excellence." If you look at the computer literature, you will see that there are two generally accepted meanings of quality. The first is that quality means "meeting requirements." With this definition, to have a quality product, the requirements must be measurable, and the product's requirements will either be met or not met. With this meaning, quality is a binary state; that is, a product is either a quality product or it is not. The requirements may be complete or they may be simple, but as long as they are measurable, it can be determined whether quality requirements have or have not been met. This is the producer's view of quality as meeting the producer's requirements or specifications. Meeting the specifications becomes an end in itself.

Another definition of quality, the customer's, is the one we use. With this definition, the customer defines quality as to whether the product or service does what the customer needs. Another way of wording it is "fit for use." There should also be a description of the purpose of the product, typically documented in a customer's "requirements specification". The requirements are the most important document, and the quality system revolves around it. In addition, quality attributes are described in the customer's requirements specification. Examples include usability, the relative ease with which a user communicates with the application; portability, the capability of the system to be executed across a diverse range of hardware architectures; and reusability, the ability to transfer software components constructed in one software system into another.

Everyone is committed to quality; however, the following show some of the confusing ideas shared by many individuals that inhibit achieving a quality commitment:

* Quality requires a commitment, particularly from top management. Close cooperation between management and staff is required to make it happen.
* Many individuals believe that defect-free products and services are impossible, and accept certain levels of defects as normal and acceptable.
* Quality is frequently associated with cost, meaning that high quality equals high cost. This is a confusion between quality of design and quality of conformance.
* Quality demands requirement specifications in sufficient detail that the products can be quantitatively measured against those specifications. Many organizations are not capable or willing to expend the effort to produce specifications at the level of detail required.
* Technical personnel often believe that standards stifle their creativity, and thus do not abide by standards compliance. However, to ensure quality, well-defined standards and procedures must be followed.