Quality audits are reviews to ensure that a company or product meets quality standards. Quality standards used for audit purposes include those set by a company or by the American Society for Quality or ASQ, International Standards Organization or ISO, American National Standards Institute or ANSI, six sigma quality standards and military specifications or milspec. Audits can also be divided by the type of auditor. Audits can also be classified based on what is being audited: the product, the process, the system.
Internal audits ensure that an organization is meeting its own quality standards or contractually required standards. This is also called a first party audit. Internal audits may be done by auditors who work for the company being reviewed. They may also be hired by the company to audit its own functions. However, auditors must be independent of the function they are auditing.
External auditors are separate from the company they are auditing because they are independent. They may be hired by a supplier or customer to ensure that the audited company meets their quality standards. They may be audited by the government to verify that they meet military specifications. External audits can be done by quality consultants specializing in the quality standards for those organizations. In all of these cases, the audit is called an external audit.
External audits done by a company that has a contract with the audited firm is called a second party audit. The second party quality audit is done by the company holding the audit.
External quality audits done by an organization that has no contract with the company it is auditing is called a third party audit. A third party external audit can be done to attain or maintain certification in a quality standard. A third party audit by an independent auditor can also be mandated by law to qualify for government contracts. A third party audit of a company can also be done at the request of a supplier or customer who would be considered a second party audit if they performed the quality audit themselves.
A process audit verifies that a documented process meets quality standards. This process could be a manufacturing process or service process.
A product quality audit verifies that a physical product meets design specifications and other quality measurements. Product audits may require measuring physical dimensions, product testing, or destructive testing. A product audit can involve checking the calibration and test equipment used to verify that the product meets quality standards.
A system audit is a review of the quality system used by a company. It is a review of how quality standards are measured and met by the company. It verifies the procedures used to measure the quality of the product, how defects are recorded, and how the company ensures that failed product is not passed.