How to Perform an Internal Audit: 4 Essential Steps for Water Labs

Think back to the last time a state agency or ISO certification body audited your water lab. How did it go? If you're hoping for a better result next time, you might want to focus on improving your internal audit program.

It's easy to gloss over internal audits in favor of more pressing tasks, but these exercises are essential to compliance. They're also critical in verifying that your lab processes are running properly and that you're collecting the most reliable data.

  FREE Best practices guide: Interpret your water testing results with confidence

To make sure you're ready for the next inspection, here's a step-by-step look at how to perform internal lab audits — from putting together an audit plan to following up on findings.

1. Create an Internal Audit Plan

Prior to conducting internal audits, you'll want to make sure you have a clear and thorough plan in place. According to the Association of Public Health Laboratories (APHL), your audit plan should include:

  • The purpose and goals of the audit, such as compliance, improving processes, or responding to a complaint.
  • The scope of the audit and the specific items you will review, such as sample data, instrument logs, procedures, and corrective actions.
  • Any standards that are relevant to lab testing, such as ISO/IEC 17025.
  • Any qualifications or training requirements internal auditors will need, as well as what responsibilities they'll have.
  • An audit schedule and sampling plan, including which processes you'll audit from start to finish (horizontal audits), and which processes you'll look at in-depth (vertical audits).
  • How you'll document and follow up on nonconformances, and how you'll record that process in your audit report.
  • A description of the effectiveness of actions over time, based on a review of corrective actions and ongoing monitoring.
  • Signatures of individuals who are responsible for audit findings and their respective dates of review.

2. Stick to Your Audit Schedule

ISO/IEC 17025 requires that labs conduct internal audits at planned intervals, though it does not specify exactly what that interval should be. The APHL recommends auditing every part of your management system at least once every year, whether that's conducting a full lab audit once a year or auditing individual parts of your system every month or quarter.

The organization also recommends giving yourself at least three to six months of lead time between an internal audit and an official inspection. Not only does this provide sufficient time to correct any problems that were identified, but you can also share lessons learned across the organization so similar issues don't occur in other areas.

The key is to create your audit schedule at the beginning of the year, and then actually stick to that schedule. It's easier said than done, but making it a priority means you won't be scrambling ahead of an official audit — and you're much more likely to avoid common compliance pitfalls.

3. Adopt a Collaborative Approach

Teams often treat internal audits and other compliance responsibilities as just another set of administrative hoops to jump through. Combined with the massive quantity of details that you need to assess, it's no surprise that many people tend to fly through audits by just checking the boxes. Audits also have a negative connotation because of their association with blaming people for problems.

To get the most of your internal audits, your lab will need to adopt a different approach. You'll want to hold the entire team responsible and focus on thoughtful, effective solutions — not play the blame game. Here are a few best practices to consider for your next compliance exercise:

  • Show respect: The auditor should treat the auditee as an equal, making it clear that the purpose of the audit is to make real improvements. Reinforce that finding issues is a good thing, as it allows your lab to proactively deal with them — before a regulator or customer has to.
  • Ask why: Always ask why when you discover a nonconformance during an audit. Auditors are often quick to jump to user error or inadequate training as the root of the issue, when in reality, your team may need more resources. For instance, a staff member might not be using an expired reagent because they're careless, but because the supplier is late in delivering the new lot.
  • Solicit ideas: Auditors should actively solicit improvement ideas and suggestions from the people they are auditing. The audit should be a two-way street, not a fault-finding exercise.
  • Fix problems: You absolutely must follow through on fixing problems uncovered during the audit — and do so within a reasonable time frame. If you don't, your employees may not take internal audits seriously and won't actively participate.

4. Follow Up on Findings

The final piece of conducting audits is closing the loop on nonconformances. Follow the procedures outlined in your audit plan, being sure to:

  • Note any high-risk findings for immediate follow-up.
  • Perform a root cause analysis to determine the most effective solution.
  • Hold responsible parties accountable for corrective action tasks.
  • Review whether corrective actions work and are upheld by revisiting them in future audits.

There's an old saying about courtroom cross-examination: Don't ask a question you don't already know the answer to. The same principle applies to audits — you don't want to have an external audit without having some idea of what auditors will find. Responding to audit findings is a critical part of ensuring that problems don't fall through the cracks.

Internal audits verify that your lab is walking the walk, not just talking the talk. When you have a comprehensive audit plan and process in place, you don't have to sweat external audits. Instead, you can go into them confident that you've already asked yourself all the tough questions.


Read These Next


Rachel Tracy
Professional Writer

Rachel Tracy is a technology and science copywriter with a background in environmental and water science. She holds a master’s degree in environmental science from Vanderbilt University and has experience working in a variety of laboratory settings, including water testing and biomedical labs. Rachel is a former environmental consultant with expertise in regulatory compliance, global management standards, and quality and safety management. She lives in Nashville, Tennessee.