Quality

In its broadest sense, quality is a degree of excellence: the extent to which something is fit for its purpose. In the narrow sense, product or service quality is defined as conformance with requirement, freedom from defects or contamination, or simply a degree of customer satisfaction. In quality management, quality is defined as the totality of characteristics of a product or service that bears on its ability to satisfy stated and implied needs (from the Institute of Quality Assurance). In statistical acceptance plans “quality” is narrowly defined as the fraction of the overall quality characteristic distribution that falls within specification limits.