Audit duration and man-days

The time needed for a certification audit is expressed in man-days (audit days). This page explains how it is determined and offers an indicative calculator based on the tables of IAF MD 5:2023.

What a man-day (audit day) is

A man-day, or audit day, is the work of one auditor for one day, normally 8 hours.

The duration of an audit is not chosen freely by the certification body. Accredited certification bodies must apply the mandatory IAF document IAF MD 5, which sets the starting point for audit time and the rules for adjusting it.

What determines the audit time

  • Effective number of personnel: all personnel working within the scope, including part-time, temporary and shift workers and, when in scope, contractors. For ISO 45001 this also includes contractors' personnel working under the organisation's control.
  • Complexity and risk of the activities: for example the environmental aspects (ISO 14001) or the occupational health and safety risks (ISO 45001) of the processes.
  • Number of sites and the activities carried out at each site.
  • Scope of certification.
  • Integration of several standards into one management system.

These factors can increase or decrease the time. Reductions cannot exceed 30% of the table value.

How the time is spread over the certification cycle

  • Initial certification audit: Stage 1 and Stage 2 together.
  • Surveillance audits: about one third of the initial audit time each year.
  • Recertification audit: about two thirds of the initial audit time, recalculated on updated data.

Indicative calculator

Indicative estimate only

Indicative estimate only. It is the starting point of IAF MD 5 before any adjustment. The actual audit time is determined by D.A.S. Certification after reviewing your application, and is stated in the offer.

Standards

Select one or more. Two or three standards are audited as an integrated management system.

Include part-time, temporary and shift workers and, when in scope, contractors.

Complexity / risk of the activities

Enter 50 for 50 or more sites.

Source: IAF MD 5:2023 (opens in a new tab) · IAF MD 11:2023 (opens in a new tab) · IAF MD 1:2023 (opens in a new tab)

See the full IAF MD 5 tables
Table QMS 1 – ISO 9001: initial audit time (Stage 1 + Stage 2), audit days
Effective personnelAudit days
1-51.5
6-102
11-152.5
16-253
26-454
46-655
66-856
86-1257
126-1758
176-2759
276-42510
426-62511
626-87512
876-117513
1176-155014
1551-202515
2026-267516
2676-345017
3451-435018
4351-545019
5451-680020
6801-850021
8501-1070022
Table EMS 1 – ISO 14001: initial audit time (Stage 1 + Stage 2), audit days
Effective personnelHighMediumLowLimited (ISO 14001 only)
1-532.52.52.5
6-103.5333
11-154.53.533
16-255.54.53.53
26-4575.543
46-65864.53.5
66-859753.5
86-1251185.54
126-17512964.5
176-275131075
276-425151185.5
426-625161296
626-8751713106.5
876-11751915117
1176-15502016127.5
1551-20252117128
2026-26752318138.5
2676-34502519149
3451-435027201510
4351-545028211611
5451-680030231712
6801-850032251913
8501-1070034272014
Table OH&SMS 1 – ISO 45001: initial audit time (Stage 1 + Stage 2), audit days
Effective personnelHighMediumLow
1-532.52.5
6-103.533
11-154.53.53
16-255.54.53.5
26-4575.54
46-65864.5
66-85975
86-1251185.5
126-1751296
176-27513107
276-42515118
426-62516129
626-875171310
876-1175191511
1176-1550201612
1551-2025211712
2026-2675231813
2676-3450251914
3451-4350272015
4351-5450282116
5451-6800302317
6801-8500322519
8501-10700342720

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