Quality Audit – Definition, Types and Process in Quality Management

An audit – in quality management also referred to as a quality audit – is a systematic, independent, and documented process for obtaining objective evidence and evaluating it objectively to determine the extent to which specified requirements are fulfilled. In quality management, the audit serves the structured assessment of management systems, processes, or products against defined criteria. An audit is not a control instrument in the operational sense, but an instrument for evaluation and insight.

Systemic Classification of Audits in Quality Management

Audits are an integral part of quality management and support the evaluation of the effectiveness of rules, processes, and systems within quality assurance. They provide structured feedback on the degree to which defined requirements are fulfilled.

Within a quality management system based on ISO 9001, audits are a central element for verifying the conformity and effectiveness of the quality management system.

Objectives and Basic Logic of Audits

The objective of an audit is to establish objectively whether specified requirements are met and whether the underlying rules are suitable for achieving the intended objectives.

The basic logic of an audit is based on:

• defined audit criteria
• systematic collection of information
• objective evaluation of evidence
• traceable documentation of the results

Audits provide insights into conformity, nonconformities, and improvement potential without prescribing actions themselves.

Types of Audits

Depending on the object under consideration and the objective, different types of audit are distinguished:

• System audit: evaluation of management systems, e.g. quality management systems
• Process audit: assessment of the effectiveness of individual processes
• Product audit: examination of products or services with regard to defined requirements

These types of audit differ in focus but follow the same methodological logic.

Internal and External Audits

Audits can also be distinguished by their organizational origin:

• Internal audits: conducted by the organization itself
• External audits: conducted by independent external bodies or customers

Internal audits primarily serve self-assessment and system improvement, while external audits frequently serve the formal assessment of conformity.

Distinction from Inspections and Tests

An audit must be clearly distinguished from inspections or tests. Inspections evaluate specific results or product properties, while audits evaluate the systematic fulfillment of requirements at system or process level.

Audits are therefore retrospective and analytical in nature, not operationally controlling.

Role of Audits in Industrial Manufacturing

In manufacturing, audits serve the structured evaluation of complex process landscapes and management systems. They support transparency about compliance and system effectiveness along the value chain.

The effect of audits can be seen at several levels:

• Organization: evaluation of system conformity
• Management: objective basis for decisions
• Processes: identification of structural weaknesses
• Culture: promotion of rule awareness and systems thinking

Normative Classification

ISO 9001 requires internal audits to be conducted to evaluate the effectiveness of the quality management system. Other standards, such as ISO 19011, describe guidelines for conducting audits without changing the character of the audit as an evaluation instrument.

Distinction from Methods, Tools, and Software

The audit is a methodological approach, not a software solution. Audit software supports planning, documentation, and evaluation, but does not replace the methodological and technical assessment.

Audit Process

An audit usually follows a fixed sequence. This makes results comparable and traceable.

1. Planning: the audit objective, scope, audit criteria, and dates are defined. Internal audits are usually part of an annual audit program.
2. Preparation: the auditor reviews relevant documents, requirements, and previous audit results and compiles a checklist.
3. Execution: the objective and procedure are explained in the opening meeting. Evidence is then collected through interviews, document review, and on-site observation.
4. Evaluation: the evidence is compared with the audit criteria. This results in findings: conformities, nonconformities, and opportunities for improvement.
5. Reporting: the results are documented in the audit report and discussed with the audited area.
6. Follow-up: corrective actions are defined for identified nonconformities. Their effectiveness is verified in the follow-up audit or separately.

Roles in an Audit

• Lead auditor: responsible for planning, conducting, and reporting on the audit.
• Auditor: examines the defined areas and documents the findings. Auditors should be independent of the audited area.
• Auditee: provides the evidence and is responsible for implementing the corrective actions.

Audit Findings: Conformity and Nonconformity

Each finding is assigned to one of these categories:

• Conformity: the requirement is fulfilled and demonstrated.
• Minor nonconformity: a single requirement is not completely fulfilled, but the effectiveness of the system is not fundamentally at risk.
• Major nonconformity: a requirement is not fulfilled, or an essential part of the system is not effective.

The exact classification depends on the applicable set of rules and the audit agreement. What matters is that every finding is substantiated by traceable evidence.

Typical Weaknesses in Audits

• Audit criteria are unclear or are not defined in advance.
• The auditor evaluates opinions instead of objective evidence.
• Nonconformities are documented without root cause analysis, so actions only address the symptoms.
• Corrective actions are not followed up, so the same nonconformities occur again in the next audit.

Practical Example: Process Audit in Series Production

A process audit checks, for example, whether inspection plans are up to date, inspection equipment is validly calibrated, process characteristics are monitored as specified, for example by means of statistical process control, and employees know the work instructions. To do this, the auditor compares the work instruction at the workstation with the inspection plan, reviews calibration records, and compiles samples of inspection results. If an inspection is not carried out as specified, this is a finding. The cause is then clarified, for example an unclear work instruction or missing training.

FAQ – Frequently Asked Questions About Audits

What is the purpose of an audit?

The purpose of an audit is the objective evaluation of whether specified requirements are fulfilled.

Is an audit a control?

No. An audit is a systematic evaluation instrument and not an operational control.

Are audits mandatory?

Internal audits are part of quality management systems based on ISO 9001, but are not required by law.

Who conducts audits?

Audits are conducted by qualified, independent persons.

Do audits lead directly to actions?

Audits identify nonconformities and insights that can form the basis for actions, but do not define them.

How long does an audit take?

That depends on the scope. A process audit of a single area often takes a few hours, a system audit covering all areas several days.

How does an audit differ from a certification?

An audit is the evaluation itself. A certification is the formal result issued by an independent certification body after a successful evaluation.

What does ISO 19011 cover?

ISO 19011 is the guideline for planning, conducting, and following up audits of management systems.

Standards and Norms

ISO 9001 (clause 9.2) requires internal audits at planned intervals to determine whether the quality management system conforms to the organization’s own requirements and to the requirements of the standard, and whether it is effectively implemented and maintained. ISO 19011 provides guidelines for auditing management systems, including the principles of auditing, the management of an audit programme, and the competence of auditors. ISO/IEC 17021-1 specifies requirements for bodies that audit and certify management systems and therefore applies to third-party certification audits. In the automotive sector, IATF 16949 (clause 9.2.2) additionally requires quality management system audits, manufacturing process audits, and product audits.

Further Internal Content

• Quality management – fundamentals
• Action management in quality management
• Audit management in the context of CAQ software

AI-assisted · Editing and publication: Christian Sedlag · Last updated: 28 October 2026