Why Audit Duration Matters for RMPs

If you’ve ever started preparing for an ISO 17034 accreditation audit, you’ve probably asked yourself: How long will this actually take?

That question matters more than most people realize. Audit duration doesn’t just affect your calendar — it drives your total cost, assessor availability, and even how much disruption your production team experiences.

In my experience helping reference-material producers (RMPs) through accreditation under SANAS, ANAB, and DAkkS, the ones who plan audit time correctly finish stronger and cheaper. This guide explains how audit man-days are calculated, what affects them, and how you can use a simple calculator to plan with confidence.

What “Man-Day” Really Means in ISO 17034 Accreditation

Every accreditation body measures audit effort in man-days — the total number of assessor working days needed to review documents, perform on-site evaluations, and prepare reports.

It’s simple math:

• 1 assessor for 1 day = 1 man-day.
• 2 assessors for 3 days = 6 man-days.

Where it gets tricky is how those days are split. Some bodies count document-review time; others bill it separately.

Pro tip: Always clarify whether desk-review hours are part of the quoted man-day total. That small detail can shift your budget significantly.

Key Factors That Drive Audit Duration

From what I’ve seen, four main factors influence how long an ISO 17034 assessment takes:

1. Scope of Accreditation – The more reference-material types and matrices you include, the more assessor time is required.
2. Number of Sites – Each production or testing site adds setup, travel, and closing-meeting time.
3. Process Complexity – A simple gravimetric mix is faster to assess than multi-step chemical syntheses or biological materials.
4. Integration with ISO/IEC 17025 – Combined assessments shorten duration because assessors review overlapping systems once.

To give you a sense of range:
A small, single-matrix RMP may need 2 assessors for 2 days (4 man-days). A multi-site operation covering several material types can stretch to 8–10 man-days easily.

Common pitfall: forgetting to include preparation and closing time. Accreditation bodies usually count these in the total man-day figure.

How Accreditation Bodies Calculate Man-Days

Even though all bodies follow ISO/IEC 17011 principles, they interpret audit-time determination slightly differently.

• SANAS (South Africa): Uses a base-plus model — a fixed number of base days plus extra time per additional material type or site.
• ANAB (U.S.): Considers both staff numbers and complexity, using a scaling formula.
• DAkkS (Germany): Follows a fixed-day approach for each activity type (initial, surveillance, reassessment).

Here’s a simplified example based on SANAS practice:

Base = 2 days + 0.5 day per additional matrix + 0.5 for production complexity

So if you have three material types and a moderately complex process:
2 + (0.5 × 2) + 0.5 = 3.5 days total

Pro tip: Request your accreditation body’s “audit-time determination” policy. It spells out exactly how they calculate man-days and helps you check if your quote makes sense.

Using a Man-Day Calculator to Plan Your Audit

A man-day calculator turns all those variables into quick, usable estimates.

Here’s what to include:

• Number of reference-material types
• Number of sites
• Staff directly involved in production or testing
• Integration with ISO/IEC 17025 (Yes/No)

Enter those and you’ll get an estimated number of man-days — plus, if you add your daily assessor rate, a ballpark audit cost.

Pro tip: Use the calculator early in your project planning. It helps you schedule staff availability, allocate budgets, and avoid last-minute resource shortages.

Example: Calculating Audit Time Step-by-Step

Let’s walk through a real scenario.

An RMP with:

• 3 technical staff
• 2 reference-material types
• 1 production site

Using a SANAS-style formula:

• Base = 2 days
• • 0.5 per material type = 1 day
• • 0.5 for complexity = 0.5 day

Total = 3.5 days ≈ 7 man-days (2 assessors)

At USD 1,000 per day, the estimated audit fee is about USD 7,000.

Pro tip: Round up partial days — accreditation bodies almost always charge whole days.

How to Optimize Your Audit Duration (Without Cutting Corners)

Over-budget audits often have one thing in common: poor preparation. You can’t shorten required man-days artificially, but you can make every hour count.

Here’s how:

• Streamline documentation. Label records clearly and organize them logically to speed up assessor review.
• Train your team. Confident staff answer faster, reducing time spent clarifying processes.
• Combine assessments. If you’re already accredited to ISO/IEC 17025, request a joint audit to share assessor time.
• Plan logistics early. Pre-arranged site access, equipment readiness, and document folders keep the schedule tight.

Skipping internal audits or rushing document prep doesn’t save time—it creates extra assessor hours later.

FAQs: ISO 17034 Audit Duration

Q1: What’s the average audit duration for ISO 17034?
Typically 4–10 man-days depending on scope, sites, and complexity.

Q2: Does integrating ISO/IEC 17025 reduce audit days?
Yes. Shared systems and records often reduce total man-days by 15–25 %.

Q3: Are remote assessments faster?
They can shorten document-review time, but on-site evaluation still takes the same number of days.

Conclusion: Estimate Early, Budget Confidently

Knowing your man-day requirement isn’t just about cost—it’s about control. When you can forecast audit time accurately, you manage resources, schedules, and expectations better.

After helping dozens of RMPs worldwide, I’ve learned this: the teams that plan audit duration from the start avoid panic, delays, and surprise invoices.

You can do the same.
Download QSE Academy’s ISO 17034 Audit-Duration Calculator to estimate your man-days instantly—or book a quick consultation if you’d like me to tailor the numbers to your exact scope.