QS-9000 (now IATF 16949) requires that the entire quality system be audited yearly. To be honesty, I m struggling to find the exact place this is stated. When I find it I will update this slide note.
QS-9000 (now IATF 16949) Requirements
Element 4.17 Internal Quality Audits
The supplier shall establish and maintain documented procedures for planning and implementing internal quality audits to verify whether quality activities and related results comply with planned arrangement and to determine the effectiveness of the quality system.
Internal quality audits shall be scheduled on the basis of the status and importance of the activity to be audited and shall be carried out by personnel independent of those having direct responsibility in the activity being audited.
NOTE: Activity can refer to departments, areas, processes, functions, etc. in a company.
NOTE: There is no specified check list that MUST be used for internal auditing purposes.
The results of the audits shall be recorded (see 4.16) and brought to the attention of the personnel having responsibility in the area audited. The management personnel responsible for the area shall take timely corrective action on the deficiencies found during the audit.
Follow-up activities shall verify and record the implementation and effectiveness of the corrective action taken (see 4.16).
20 The results of internal audits form an integral part of the input to management review activities (see 4.l1.3.)
21 Guidance on quality system audits is given in ISO 10011.
4.17.1 Internal Audit Schedules
Internal auditing should cover all shifts and be conducted according to an audit schedule updated annually. When internal/external nonconformances or customer complaints occur, the planned audit frequency should be increased.
ISO 19011 - Quality and Environmental Management Systems Auditing Forum Discussions