Last Updated on September 25, 2025 by Melissa Lazaro

ISO/IEC 17043:2023 Process Requirements (Clause 7) – Complete Guide

Let’s be honest—Clause 7 is where everything comes together. You can have great staff and perfect equipment, but if your PT scheme isn’t well-planned, fairly evaluated, and clearly reported, people lose trust. Fast.

In my experience helping PT providers prepare for accreditation audits, this is where most systems either shine or struggle. The good news? Clause 7 doesn’t have to be complicated. If you take a step-by-step approach and document what you’re already doing well, you’re halfway there.

What you’ll get from this guide:
We’ll walk through each part of Clause 7—from scheme design to complaints—so you can tighten your process, reduce risk, and run better programs overall.

What Clause 7 Is Really About

Clause 7 isn’t just a list of to-dos. It’s a roadmap for delivering PT schemes that are fair, scientifically sound, and genuinely helpful to participants.

It includes requirements for:

• Designing your scheme
• Preparing and handling PT items
• Collecting and evaluating data
• Reporting results
• Dealing with complaints and underperformance
• Protecting confidentiality and impartiality along the way

This is the “how” of proficiency testing—not just what you do, but how you do it well.

 

Designing the Scheme – Where Everything Starts

Before you ship a single PT item, you need a plan. A good one.

This section should cover:

• Scheme objectives: What are you testing, and why does it matter?
• Scope and type of PT: Is this a comparison of results? Calibration? Identification?
• Technical design: How will items be prepared, distributed, and evaluated?
• Timeline: When will samples go out? When are results due?
• Participant instructions: Clear, accessible, and complete

Pro tip: Keep a record of how and why decisions were made during scheme design. It helps during audits and when refining future rounds.

Preparing and Handling PT Items – Keeping It Real (and Reliable)

This part is often underestimated. Clause 7 expects you to make sure PT items:

• Are clearly labeled and tracked
• Remain stable and homogeneous until they reach participants
• Are handled in a way that prevents contamination, confusion, or loss of integrity

This includes having procedures for:

• Packing and labeling
• Storage and temperature control
• Distribution and transit monitoring

Common pitfall: Assuming homogeneity or stability without evidence. Even for simple materials, do a basic check and document it.

Data Collection – Don’t Let Results Go Off the Rails

Once participants start sending in results, you need a system—preferably one that’s secure, organized, and backed up.

Clause 7.6 expects that:

• Data is submitted within a defined timeframe
• You have a process for accepting, checking, and storing submissions
• Errors or gaps are identified and flagged before analysis

Whether it’s an online portal or a spreadsheet, the key is control. Know who can access the data, how it’s validated, and how late submissions are handled.

Real-world insight: A provider I worked with lost credibility after accepting emailed results with no version control. One mix-up, and the wrong results got analyzed. Lesson learned.

Evaluation of Participant Performance – Be Fair, Be Transparent

This is where PT really proves its value—but only if the evaluation is done properly.

Clause 7.7 wants to see:

• A defined method of evaluation (z-score, En value, expert review, etc.)
• Consistent application of performance criteria
• Documentation of how assigned values and standard deviations were determined
• A clear explanation of what makes a result acceptable or not

Important: Whatever evaluation model you use, make sure participants know it ahead of time. Surprises are for birthday parties—not performance scoring.

Reporting Results – Make It Clear, Make It Count

Clause 7.8 requires that reports are:

• Clear and unambiguous
• Issued in a timely manner
• Include assigned values, statistical treatment, and performance assessment
• Explain the significance of the results to participants

Pro tip: Include a “how to interpret your results” page or glossary. It’s helpful, especially for less experienced labs.

Avoid this mistake: Sending out final reports with no review step. Even small typos or mislabeling can cause confusion or distrust.

Dealing with Unsatisfactory Performance – Handle It with Professionalism

This one can be awkward. Nobody enjoys telling a lab they didn’t do well. But Clause 7.9 says you have to handle it clearly and consistently.

Here’s what you’ll need:

• Criteria for defining unsatisfactory performance
• A process for informing participants promptly
• Options for investigation, feedback, or corrective actions
• Records of communication and follow-up

Tone tip: Focus on improvement, not blame. Many providers offer optional re-testing or feedback sessions to help labs learn from errors.

Handling Complaints and Appeals – It’s Not About Being Perfect

Every PT provider gets complaints. What matters is how you handle them.

Clause 7.10 requires that:

• You have a documented complaint and appeal procedure
• It’s accessible and transparent to participants
• Complaints are logged, reviewed, and resolved within a reasonable time
• There’s no conflict of interest in the review process

What I’ve seen work: Keep a simple complaints log (even a spreadsheet) with dates, actions taken, and outcomes. Show that you listen, act, and learn.

Safeguarding Confidentiality and Impartiality – It’s Everyone’s Job

Clause 7.11 is the quiet backbone of the whole process.

You need to:

• Protect participant identities during analysis and reporting
• Ensure no one evaluating results has a personal or professional bias
• Prevent favoritism or retaliation in scheme operations
• Maintain secure records and restrict access appropriately

Simple safeguard: Use anonymized participant codes and lock evaluation files with controlled access.

Pro Tips – Practical Advice You Can Actually Use

Here’s what I’ve learned from years of helping PT providers get accredited and stay sharp. These aren’t theoretical suggestions—these are real fixes that have helped teams streamline their process and reduce nonconformities under Clause 7.

Pro Tip 1: Build a visual scheme calendar and assign owners.
Most PT programs involve a lot of moving parts—sample prep, shipment windows, deadline reminders, data reviews, report approvals. That’s a lot to manage, and it’s easy for something to slip through. Create a master calendar for each scheme. It doesn’t have to be fancy; a spreadsheet, online project tool, or even a whiteboard works fine. What matters is that it’s visible, shared with your team, and includes responsibilities. This will help avoid deadline surprises and make handoffs between team members smoother.

Pro Tip 2: Use standard templates to reduce confusion and rework.
Inconsistent or unclear documentation is a common root cause for complaints. I’ve seen it time and time again—a participant misreads unclear instructions, or a new staff member edits the wrong version of a result template. By standardizing your forms—submission sheets, participant instructions, evaluation reports—you eliminate confusion and maintain a clean, controlled process. Bonus: this also makes internal reviews faster and makes a good impression on auditors.

Pro Tip 3: Run a mini post-scheme debrief to capture lessons learned.
You don’t need a full-blown management review after every scheme. But taking twenty to thirty minutes to sit with your team and ask, “What worked?” and “What should we fix next time?” is worth its weight in gold. Document the insights—even informally. This keeps your improvement process alive and helps avoid repeating the same mistakes in future rounds.

Pro Tip 4: Appoint someone to review everything from the participant’s point of view.
This is one of my favorite low-effort, high-impact moves. Ask a team member—ideally someone who hasn’t worked on that specific scheme—to walk through the instructions, submission form, and report as if they were a participant. Their feedback can uncover things you’ve missed: confusing language, unclear deadlines, or even formatting errors. You’ll improve the user experience and reduce the number of helpdesk emails.

Pro Tip 5: Document your evaluation logic clearly—not just the outcome.
It’s one thing to calculate z-scores or assign values; it’s another to explain how and why you chose that method. Whether you’re using statistical models or expert judgment, record your rationale. For example, why did you choose robust statistics instead of classical? Why did you discard certain outliers? Writing this down—especially when it’s outside the usual templates—shows consistency and gives you a strong defense during audits or disputes.

Pro Tip 6: Track and analyze informal feedback.
Not all feedback comes in the form of formal complaints. Sometimes, participants will casually mention that a shipment was late or the sample label was hard to read. Don’t ignore these. Start a simple log—even a shared doc—where you note date, scheme, who said what, and any follow-up. Over time, this log becomes a powerful tool for identifying patterns and proactively improving your schemes before issues escalate.

Common Mistakes to Watch For

• No written justification for evaluation criteria
• Forgetting to notify participants about changes or delays
• No follow-up on labs with poor performance
• Rushing reports without final review
• Handling complaints informally with no documentation

FAQs – Straight Answers

Do we need to evaluate all participants the same way?
Yes—unless there’s a justified reason. Be fair and apply the same criteria to everyone.

Can we use expert judgment instead of z-scores?
Absolutely—but explain how it’s applied and document your reasoning.

How soon should results be reported?
As soon as possible after the closing date. Define the timeline in your plan and stick to it.

Do we need to inform participants about complaints received?
Not unless it affects them. But you should always respond to the complainant and record how it was handled.

Clause 7 Is Where You Prove Your Value

Your PT scheme lives and dies by its process. Clause 7 of ISO/IEC 17043:2023 isn’t just about ticking off requirements—it’s about earning trust. When your processes are solid, transparent, and fair, you build confidence with both your participants and your assessors.

So here’s your action step:
Pick one active scheme. Walk through every Clause 7 requirement. Is it documented? Repeatable? Fair? If not—now’s the time to improve it.

And remember, you don’t have to figure it all out alone. If you ever need help fine-tuning your process or preparing for an audit, I’m here to help.