Last Updated on October 17, 2025 by Melissa Lazaro

Turning Laboratory Processes into Consistent, Defensible Results

When I train labs for ISO 15189 accreditation, Clause 7 is where things get real. This clause covers everything that happens to a sample—from the moment it’s collected to the time a validated report reaches the client.

Here’s what I’ve noticed: most labs are technically sound but process-weak. They run great tests, yet their documentation, traceability, or reporting practices don’t fully support those results. Clause 7 fixes that. It helps you build a chain of control so strong that every result can be defended with confidence.

In this section, we’ll break down Clause 7 into practical steps—so you can build processes that run smoothly, meet auditor expectations, and protect patient trust

Understanding ISO 15189:2022 Clause 7 – Why Process Control Is the Heart of the Standard

Clause 7 is the engine of ISO 15189—it’s where the science meets the system. While other clauses focus on structure, people, and policies, this one focuses on how work actually happens inside your lab.

Here’s what it covers: everything from how you receive a sample, to how you test it, to how you report the results. It’s divided into three main stages:

• Pre-examination – activities before testing, like collection and labeling.

• Examination – the actual analysis and testing process.

• Post-examination – reporting, reviewing, and storing results.

Clause 7’s main goal is simple but strict: every process must be validated, controlled, traceable, and consistent—no matter who performs it or when.

Here’s what I’ve seen trip up labs: they treat each phase as a separate task owned by different teams. But assessors see it as one continuous process. If a mistake happens in pre-exam, it affects everything downstream.

Pro Tip: Map your full workflow—from sample collection to result reporting—and identify every control point. When you visualize it, weak spots become obvious.

Common Pitfall: Focusing too much on the examination stage. Nonconformities often come from pre- or post-examination gaps, not the testing itself.

Pre-Examination Process – Getting the Sample Right from the Start

Every reliable result begins with a reliable sample. Clause 7 starts here for a reason—if the pre-examination process fails, no amount of technical skill later can fix the damage.

Here’s what this phase includes: patient preparation, sample collection, labeling, transportation, and receipt. In short, it’s everything that happens before the test starts.

In my experience, this is where most nonconformities appear. Labels that don’t match requisitions, samples that sat too long in transit, or missing temperature logs—all of these break the traceability chain.

To stay compliant:

1. Standardize sample collection. Provide clear instructions for clinicians or phlebotomists, including sample type, volume, and storage conditions.

2. Use unique identification. Barcoded or digitally logged samples reduce mix-ups and manual errors.

3. Document transport conditions. Record temperature, time, and courier details for every shipment.

4. Inspect upon receipt. Reject or quarantine compromised samples immediately.

Pro Tip: Keep a “Sample Acceptance Log” that lists who received each sample, the condition on arrival, and actions taken if it was rejected. It’s one of the first documents auditors will request.

Example: One hospital lab I supported reduced sample rejection rates by 60% after implementing standardized collection kits and training clinicians on labeling procedures.

Common Mistake: Ignoring external collection sites. ISO 15189 requires that all collection procedures—whether in-house or offsite—follow your documented requirements.

Examination Process – Performing Validated and Controlled Analyses

This is the phase most labs feel confident about—because it’s where the science happens. But Clause 7 doesn’t just care that you perform tests correctly; it cares that every method is validated, verified, and controlled before use.

Here’s the key idea: your results must be technically sound and defensible. That means every test method, instrument, and reagent must produce results that meet defined accuracy, precision, and traceability requirements.

Here’s what compliance looks like in practice:

1. Method Selection: Use methods appropriate to your scope and intended use—whether standardized or developed in-house.

2. Validation and Verification: Validate new or modified methods; verify manufacturer-provided ones before routine use.

3. Quality Control: Run internal QC with every batch and track trends over time.

4. Traceability: Ensure calibration and measurement results link to recognized standards.

5. Documentation: Record all validation data, QC results, and corrective actions.

Pro Tip: Create a Method Verification File for each test. Include validation data, acceptance criteria, QC results, and authorization records. It’s your one-stop evidence folder for auditors.

Example: One clinical chemistry lab I assisted failed an initial audit because they relied solely on manufacturer validation data. After performing local verification—comparing precision, accuracy, and linearity with their own samples—they passed their reassessment with zero findings.

Common Pitfall: Treating validation as a one-time task. ISO 15189 expects periodic re-evaluation, especially after equipment servicing, reagent changes, or method updates.

Post-Examination Process – Reporting, Reviewing, and Storing Results

Once testing is complete, the focus shifts to how results are handled—and this is where many labs lose points during audits. Clause 7’s post-examination section ensures your reporting process is accurate, traceable, and secure. It’s the last mile of quality control before your findings reach a patient, doctor, or client.

Here’s what this stage involves:

1. Verification and authorization – Every result must be reviewed and approved by an authorized individual before release.

2. Report format and clarity – Reports must include patient identifiers, date and time of analysis, units, reference ranges, and the name of the approver.

3. Data transmission and confidentiality – Whether reports are printed, emailed, or uploaded electronically, they must be transmitted securely and only to authorized recipients.

4. Record retention – Results, raw data, and audit trails must be stored in a way that preserves accuracy and confidentiality for the defined retention period.

Pro Tip: Create a Result Release Checklist that reviewers complete before final sign-off—covering accuracy, completeness, and formatting. This simple tool shows auditors you have a structured verification process.

Example: A clinical lab I worked with implemented dual verification for critical results—one by the analyzer operator and another by the section head. Their report-correction rate dropped by nearly 40% within three months.

Common Pitfall: Rushing result release. Skipping verification or neglecting to document who approved a report can lead to major nonconformities under Clause 7.

Handling Nonconforming Work – What to Do When Things Go Wrong

Even the best laboratories face errors at some point—what matters is how you handle them. Clause 7 requires a structured system for identifying, documenting, and correcting nonconforming work before it affects clients or patient safety.

Here’s what that looks like in real life:

1. Identify quickly. Any staff member should be empowered to report a potential issue—wrong sample ID, instrument failure, reagent contamination, or QC failure.

2. Segregate immediately. Stop the affected process, label the samples as “On Hold,” and prevent results from being released until the issue is resolved.

3. Evaluate the impact. Determine which tests, reports, or patients might be affected and notify clients if needed.

4. Correct and record. Fix the issue, record what happened, and document your corrective and preventive actions.

Pro Tip: Keep a Nonconforming Work Register that logs the incident, impact, root cause, and actions taken. It’s one of the first things assessors review to evaluate your problem-solving process.

Example: A microbiology lab I worked with caught an autoclave malfunction through routine QC. They immediately halted affected testing, documented the issue, and verified sterilization effectiveness before resuming. Because they followed procedure, the assessor praised their response rather than penalizing the failure.

Common Pitfall: Fixing the symptom but not the root cause. Auditors look for analysis that shows why an error happened—not just that it was corrected.

Quality Control, Assurance, and Result Validity

Clause 7 doesn’t stop once a test is performed—it demands that you continuously prove the results are valid. This is where quality control (QC) and quality assurance (QA) come into play. They’re the backbone of your laboratory’s credibility.

Here’s how to make it work in practice:

1. Internal Quality Control (IQC): Run control samples with every batch, track results over time, and investigate any trends or shifts immediately.

2. External Quality Assessment (EQA): Participate in proficiency testing programs and review results critically.

3. Ongoing Method Evaluation: Check linearity, reproducibility, and calibration stability regularly—especially after reagent changes or maintenance.

4. Result Validity Checks: Implement procedures to detect and correct abnormal or inconsistent results before they’re reported.

Pro Tip: Visualize your QC data. Levey-Jennings or moving-average charts make trends easy to spot, and auditors love seeing that level of oversight.

Example: One clinical chemistry lab I worked with began plotting daily QC data instead of just storing it. Within a month, they detected a gradual analyzer drift that had gone unnoticed for weeks. Early detection saved them from costly rework and a potential nonconformity.

Common Pitfall: Reacting to QC failures without documenting investigations or outcomes. ISO 15189 expects clear records of what went wrong, how it was fixed, and how recurrence will be prevented.

Traceability, Records, and Documentation

If Clause 7 had a theme song, it would be “Show me the proof.” Every step in your process—from sample collection to report delivery—must be traceable, recorded, and verifiable. Traceability is how you prove that your lab’s results are built on documented control, not assumptions.

Here’s how to stay compliant:

1. Record every step. Each sample must be linked to a request form, collection record, test method, equipment, reagents, and the personnel involved.

2. Control your records. Keep logs secure, legible, and accessible. Whether on paper or in a LIMS, every change must be traceable with dates and signatures.

3. Connect everything. A result should be traceable back to the reagents, calibration standards, and instruments that produced it.

4. Retention and retrieval. Follow defined retention times for all records and ensure you can retrieve them quickly during audits.

Pro Tip: Use a Traceability Map or flow diagram that shows the links between patient, sample, method, instrument, and report. It’s an excellent visual proof for assessors.

Example: A hematology lab I worked with linked its instrument logs to individual patient reports through its LIMS. When an auditor asked for evidence of calibration for a specific test, the team produced it in under a minute—and the assessor noted it as “best practice.”

Common Pitfall: Keeping incomplete or inconsistent records. Missing dates, initials, or version numbers make auditors question your control—even if your testing is accurate.

Continuous Monitoring and Improvement of Laboratory Processes

Clause 7 doesn’t end with documentation—it expects you to learn from your own data. Continuous monitoring and improvement are what separate a compliant lab from an exceptional one.

Here’s the mindset: every error, delay, or client complaint is a clue about how your process can get better. ISO 15189 wants you to spot those patterns early, fix the cause, and prove that your lab evolves through feedback and evidence.

Here’s how to make it work:

1. Track process KPIs. Measure things like turnaround time, sample rejection rates, QC failures, or report corrections.

2. Hold regular process reviews. Discuss trends in internal audits, QC, and customer feedback during management meetings.

3. Document every improvement. When you change a process, update your SOPs and record the reason—it shows proactive control.

4. Involve your staff. Encourage them to suggest improvements; they’re often the first to see where bottlenecks or risks appear.

Pro Tip: Create a “Process Improvement Tracker” with sections for the issue, root cause, action taken, and measurable outcome. It gives you a ready-made improvement log for assessors.

Example: A diagnostics lab I supported used turnaround-time data to identify delays in the pre-examination phase. By adjusting courier schedules, they cut total processing time by 25%—and customer satisfaction shot up.

Common Pitfall: Treating improvement as an annual task. Continuous monitoring means constant learning, not a box you check before an audit.

FAQs – ISO 15189 Clause 7 Explained

Q1: What’s the most common Clause 7 nonconformity?
In my experience, it’s missing traceability between stages. A lab might handle samples perfectly during testing but can’t show how they were received, labeled, or transported. Without full traceability, the result can’t be trusted.

Q2: How can small labs comply with Clause 7 without expensive systems?
You don’t need fancy software. Start with well-structured logs and checklists—sample receipt forms, QC logs, and report verification sheets. Consistency is more important than technology.

Q3: Do we need to validate every single method?
Yes—but to the right extent. Commercially established methods require verification to confirm they work in your environment. Only new or modified methods require full validation.

Q4: How can we prove continual control over all processes?
Link your documentation. Show that each process (pre-, exam, post-) has SOPs, logs, and review records. During audits, being able to trace one sample through every phase is the ultimate proof of control.

Build Processes That Inspire Confidence

Clause 7 is where quality stops being theory and becomes reality. It’s the part of ISO 15189 that proves your lab doesn’t just have a system on paper—it lives it every day.

When every process is defined, validated, and traceable, you build more than compliance—you build trust. Doctors, patients, and assessors can rely on your results because they’re backed by evidence, not assumptions.

Here’s what I’ve seen in top-performing labs:

• They view each test as a complete story—from sample to report.

• They empower staff to question, record, and improve every process.

• They use data, not luck, to prove consistency and reliability.

If you follow Clause 7 step by step, your lab’s processes will not only pass audits—they’ll perform better, faster, and with fewer errors.

Next Step: Download QSE Academy’s ISO 15189:2022 Clause 7 Process Toolkit—you’ll get pre-exam, exam, and post-exam templates, nonconformity logs, and validation checklists designed to help your team build bulletproof processes that impress auditors and protect patient trust.