Determination and Justification of Audit Time


During recent Accreditation Body Assessments it was identified that WCS and all Accredited Certification Bodies are required to make available to its customers the justification for determining effective number of employees and the justification for audit time determination. This requirement is included in IAF MD 5 and this relates to ISO 9001, ISO 14001 and AS 9100 clients.

WCS retain in client files the effective number of employees for each client. Likewise the audit calculation (justification) is retained on file. This is available to all clients on request.

WCS will be adding a reference to this on all future certification contracts. In order to make it clear to all current clients WCS is providing the following justification on how it determines audit time.

Effective Number of Employees

AS 9100 – Audit duration in the As 9100 Certification Scheme is based on Total Number of Employees (not effective number).

ISO 9001 / ISO 14001 / ISO 45001 – WCS will ask each applicant for a breakdown of employees in the main processes or areas of the business. WCS will ask about temporary workers, part time workers and full time workers. WCS reviews the number of employees in each area and makes a decision on the effective number. Example below:

100 cleaners doing domestic house cleaning – WCS may reduce this significantly so the effective number is 30. WCS will retain this information on file.

Audit Duration Calculation

WCS determines the audit duration in accordance with IAF MD5, IAF MD 22, and AS 9104 requirements. WCS consider factors such as risk, size/complexity, degree of regulation, temporary sites, outsourced processes, level of automation, repetitive processes, high number of staff undertaking similar simple functions etc.  WCS retain all calculations on file for review by a client on request and for accreditation bodies during routine audits. WCS use the starting audit duration within IAF documentation and reduce / increase the audit time considering the factors above.

In general the initial audit duration is calculated, the surveillance audit is approx. 1/3 of the initial audit duration and recertification is approx. 2/3 of initial audit duration.


WCS will discuss the audit duration on application for certification services. Determination of audit duration (calculation) is available on request. Please email if you require this information. Note that this information is confidential and remains the property of World Certification Services Ltd. The information should not be forwarded on to third parties without the permission of World Certification Services Ltd.