Scoping
Audit duration estimator
Audit days are not a quote and not a negotiation. They are derived from the effective number of personnel in scope, the number of sites, and complexity — the same basis every accredited body works from. This gives you the range before you talk to anyone.
How this is calculated
A base duration is read from the effective-personnel table, then adjusted for complexity and for sites — sub-linearly, because sampling is permitted where the management system is genuinely common across locations. Additional schemes carry a reduction when audited together.
Stage 1 is roughly a fifth of the initial effort. Surveillance runs about a third of the initial audit, annually. Recertification in year three is a full re-audit.
Methodology follows IAF MD 5 and ISO/IEC 17021-3. The output is indicative. Actual duration is set at scoping and signed off by a scheme manager who has seen your boundary.