The term “quality” means different things to different people in different circumstances. For example, the International Standards Organization (ISO) defines quality as “the degree to which a set of inherent characteristics fulfills requirements”, where “requirement” means need or expectation. Joseph M. Juran defines quality as “fitness for use”, with fitness being defined by the customer.
However, the most common expectation of a “quality” product or service is that it meets certain pre-defined or generally well-accepted criteria. Conversely, as defined by the American Society for Quality (ASQ), the term quality can mean “a product or service free of deficiencies.”
At the most basic level, the seller of any product or service has a moral (and usually contractual) obligation to meet or exceed the customer’s requirements for the intended or implied use of the product or service. As Peter Drucker says “Quality in a product or service is not what the supplier puts in. It is what the customer gets out and is willing to pay for.” Ultimately, the responsibility for satisfying a customer’s quality expectations rests with the supplier.
How do quality control (QC) and quality assurance (QA) differ?
As might be expected, the use of the terms “quality control” and “quality assurance” are not universal, as is highlighted in the differences between public and private sector application.
For United States federal government suppliers, quality control includes the procedures and processes that a supplier uses to ensure that any supplies or services tendered for acceptance meet contract requirements. In contrast, quality assurance includes the various functions the government uses to determine whether the supplier has fulfilled contract obligations pertaining to quality and quantity. QA procedures are used to validate the supplier’s QC approach.
In the private sector, however, QA is defined as a procedure or set of procedures intended to ensure that a product or service under development (before work is complete, as opposed to afterwards) meets specified requirements. QC, on the other hand, is a procedure or set of procedures intended to ensure that products or performed services adhere to a defined set of quality criteria or meet the requirements of the client or customer.
Unless otherwise indicated, ThinkQ uses the terms and definitions for QC and QA as defined by the US federal government.
