The goal of these standards is to help organizations ensure that they meet customer and other stakeholder needs within the statutory and regulatory requirements related to a product or service.

[3] ISO 9000 deals with the fundamentals and vocabulary of QMS,[4] including the seven quality management principles that underlie the family of standards.

Over one million organizations worldwide[10] are independently certified, making ISO 9001 one of the most widely used management tools in the world today.

Large organizations that supplied government procurement agencies often had to comply with a variety of quality assurance requirements for each contract awarded, which led the defense industry to adopt mutual recognition of NATO AQAP, MIL-Q, and Def Stan standards.

In the early days, the ISO 9001 (9002 and 9003) requirements were intended to be used by procuring organizations, such as contractors and design activities, as the basis of contractual arrangements with their suppliers.

The ISO 9001 requirements could be tailored to meet specific contractual situations, depending on the complexity of the product, business type (design responsibility, manufacture only, distribution, servicing, etc.

[18] [19] If a chosen supplier was weak in the controls of their measurement equipment (calibration), and hence QC/inspection results, that specific requirement would be invoked in the contract.

A few years later, the UK Government took steps to improve national competitiveness following the publication of a white paper on Standards, Quality and International Competitiveness, Cmd 8621,[20] and Third-Party Certification of Quality Management Systems was born under the auspices of the National Accreditation Council of Certification Bodies (NACCB), which has become the United Kingdom Accreditation Service (UKAS).

[23] Heras et al. found similarly superior performance[23] and demonstrated that this was statistically significant and not a function of organization size.

[24] Naveha and Marcus claimed that implementing ISO 9001 led to superior operational performance in the U.S. automotive industry.

[28] While the connection between superior financial performance and ISO 9001 may be seen from the examples cited, there remains no proof of direct causation, though longitudinal studies, such as those of Corbett et al. (2005),[23] may suggest it.

Other writers, such as Heras et al. (2002),[24] have indicated that while there is some evidence of this, the improvement is partly driven by the fact that there is a tendency for better-performing companies to seek ISO 9001 certification.

Sections 1 to 3 are not directly audited against, but because they provide context and definitions for the rest of the standard, not that of the organization, their contents must be taken into account.

The organization must demonstrate how the standard's requirements are being met, while the external auditor's role is to determine the quality management system's effectiveness.

[44] An organization applying for ISO 9001 certification is audited based on an extensive sample of its sites, functions, products, services, and processes.

[45] There are no grades of competence within ISO 9001: either a company is certified (meaning that it is committed to the method and model of quality management described in the standard) or it is not.

ISO 9000:1994 emphasized quality assurance via preventive actions, instead of just checking final product, and continued to require evidence of compliance with documented procedures.

As with the first edition, the down-side was that companies tended to implement its requirements by creating shelf-loads of procedure manuals, and becoming burdened with an ISO bureaucracy.

The 2000 version sought to make a radical change in thinking by actually placing front and center the concept of process management (the monitoring and optimization of a company's tasks and activities, instead of just inspection of the final product).

For example, in ISO 9001:2008, a quality management system being upgraded just needs to be checked to see if it is following the clarifications introduced in the amended version.

This moment was considered by important specialists in the field as the "beginning of a new era in the development of quality management systems".

[48] The new ISO 9001:2015 management system standard helps ensure that consumers can secure reliable, desired quality goods and services.

This was achieved by combining the process approach with "risk-based thinking", and employing the Plan-Do-Check-Act cycle at all levels in the organization.

[52] The ISO and the International Accreditation Forum (IAF) have issued joint guidance on auditing practices covering risk-based thinking.

The aim is a continual review and assessment process to verify that the system is working as it is supposed to, find out where it can improve, and correct or prevent identified problems.

It is considered healthier for internal auditors to audit outside their usual management line to bring a degree of independence to their judgements.

Diverse organizations—police departments (United States), professional soccer teams (Mexico), and city councils (UK)—have successfully implemented ISO 9001 systems.

[12] One study showing reasons for not adopting this standard include the risks and uncertainty of not knowing if there are direct relationships to improved quality, and what kind and how many resources will be needed.

[61][64] ISO's Roger Frost suggested: "If you just want the certificate on the wall, chances are you will create a paper system that doesn't have much to do with the way you actually run your business.