Audit Day Table

How many audit days would a certification body (registrar) estimate for your initial stage 1 and stage 2 certification audit, ongoing surveillance visits, or re-certification audit?

The International Accreditation Forum (IAF) provides Mandatory Documents (MD 5:2009 and MD 9:2011) to certification bodies that contain mandatory provisions and guidance on the time required to audit their clients. MD 5:2009 applies to quality management systems (ISO 9001) and environmental management systems (ISO 14001). MD 9:2011 applies to medical device quality management systems (ISO 13485).

The effective number of personnel indicated in the audit day table below consists of all full-time personnel within the scope of the certification, including those working on each shift. Non-permanent (seasonal, temporary, and contracted personnel) and part-time personnel who will be present at the time of the audit are included in the numbers. Dependent on the hours worked, the part-time personnel numbers can be converted to an equivalent number of full-time personnel.


(Compiled from tables in Annexes A and B of MD 5 and Annex D of MD 9)

Note 1: View number of employees as continuum rather than stepped change.
Note 2: High, Medium, Low, and Limited are complexity categories. See Table EMS 2 in MD 9.

MD 5 states the audit duration for all types of audits includes on-site time at a client’s premises and time spent off-site carrying out planning, performing document review, interacting with client personnel, and writing the report. The off-site activities should not reduce the total on-site audit duration to less than 80% of the times shown in the tables above. The audit days are based on eight hours per day. The audit days cannot be reduced by planning on longer hours per working day.

MD 9 adds that the duration for ISO 13485 audits will be dependent on the audit scope, objectives, and specific regulatory requirements, as well as, on the range, class, and complexity of medical devices, and the size and complexity of the organization.

Surveillance Audits

During the initial three-year certification period, surveillance audits should be proportional to the time spent on the initial certification audit. The total amount of time spent annually on surveillance audits should be about 1/3 the time spent on the initial certification audit (stage 1 + stage 2). Surveillance audit duration in future periods should take into account organizational changes and system maturity.

Re-Certification Audits

The re-certification audit is normally 2/3 of the time spent on the initial certification audit (stage 1 + stage 2). Future re-certification audits should be based on the time that would be required for the initial certification audit if it were to be carried out at the time of re-certification (not 2/3 of the original initial certification audit). The audit duration should also take into account the review of system performance.

Adjustment Factors

Increase the Days
MD 5 identifies factors to consider for possibly increasing the duration of ISO 9001 and ISO 14001 audits as complicated logistics, multiple languages, large physical site, highly regulated, and complex processes.

MD 9 states the duration may be increased for ISO 13485 audits due to the number of ranges and/or complexity of medical devices, use of critical suppliers without sufficient evidence of conformity (may have to audit suppliers), manufacturers that install products at customer’s premises (may have to visit customers or review installation records), and poor regulatory compliance.

Decrease the Days
MD 5 considerations for decreasing the duration for ISO 9001 or ISO 14001 audits include factors such as excluded requirements, system maturity, other certifications, identical shifts, multiple sites, and low complexity. The guidance states a reduction in audit duration would be unlikely to exceed 30% of the times established from the tables.

MD 9 states that the duration for ISO 13485 audits may be decreased based on reductions of the manufacturing product range, or design and production processes, since the last audit.

Table Intent

The tables are frameworks for audit planning and making adjustments to audit duration for all types of audits. The intent is to lead to consistency of audit duration between certification bodies, as well as, between similar clients of the same certification body.

You can view or download copies of MD 5:2009 and MD 9:2011 at this IAF web page.