LOPA Revalidation - How to know if it’s time to revisit

Your Layers of Protection Analysis (LOPA) can be critical part of your site’s operation and safety. By initiating a LOPA you ultimately gain more granular insight into existing processes and systems to clearly identify (and therefore mitigate) risks. If you haven’t performed a LOPA within your organization you should strongly consider the benefits it can provide, and as with all processes, it would be smart to reconsider whether you need to revisit your previous analysis. LOPA revalidation is the smartest and efficient way to maintaining the integrity of your process safety management (PSM) program. Revisiting and re-evaluating your existing plan can identify previous assumptions that are no longer true, missed MoC integration, or mitigation costs that can be lowered. 

At McMillen Process Safety, we have helped organizations and companies strengthen their operations via increased safety, smart mitigations, and renewed process awareness. 

What Is LOPA Revalidation? 

A LOPA (Layer of Protection Analysis) evaluates the adequacy of safeguards in preventing or mitigating hazardous events. It bridges the gap between qualitative hazard analysis methods like HAZOPs and more detailed quantitative risk assessments.  LOPAs will provide refinement to Causes which lead to Initiating Events (IE) which then allow for the use of Industry Failure Rates (aka Probability of Failure on Demand (PFD)). These can then be looked up in published tables and coupled with site specific maintenance including incident data.  LOPAs will also refine safeguards to assign typical Industry Risk Reduction Frequencies (RRFs) which can be looked up in published tables.  This statistical data will allow for the removal of the emotional/subjective nature of a HAZOP into a semi-qualitative risk analysis. 

LOPA revalidation is the process of reviewing and updating those analyses over time; ensuring that assumptions, safeguards, and risk tolerance criteria still reflect the current reality of your facility. 

Revalidation typically occurs every five years (in line with OSHA’s PSM requirements), directly after the HAZOP sessions or sooner when significant process, personnel, or equipment changes occur. 

Why It Matters 

Over time, operations evolve: 

• Processes change. Equipment gets upgraded, control systems are modernized, or throughput increases. 

• Safeguards degrade. Alarms are bypassed, instrumentation drifts, and procedural controls slip. 

• People rotate. Institutional knowledge fades, and new operators may not fully understand the original risk assumptions. 

• Company Maturity increases. 

Without revalidation, a once-accurate LOPA may no longer reflect the actual protective layers in place, leaving unseen gaps between intended and real-world protection. 

Regular LOPA revalidation ensures your facility’s Independent Protection Layers (IPLs) remain effective, realistic, and aligned with your organization’s risk tolerance and compliance goals. It also demonstrates due diligence to regulators, insurers, and stakeholders. 

How McMillen Process Safety Adds Value 

At McMillen Process Safety, we approach LOPA revalidation as more than a compliance checkbox ... it’s an opportunity to improve safety performance, operational reliability, and organizational understanding of risk.

Our team brings a structured yet collaborative approach: 

1. Preparation & Data Gathering -  We begin by reviewing previous LOPA and HAZOP documentation, change management records, and incident data to identify what’s changed since the last review. 

2. Facilitated Revalidation Sessions - Using seasoned facilitators, we engage cross-functional teams — operators, engineers, and maintenance personnel — to reassess causes, consequences, and safeguards with clarity and efficiency. 

3. Verification of IPLs - Each safeguard is re-evaluated to confirm it still meets the criteria for independence, reliability, auditability, and effectiveness. We also identify where layers have eroded or could be enhanced. 

4. Risk Gap Identification & Recommendations - We highlight risk gaps and help you prioritize corrective actions with practical, cost-effective solutions that align with your operational goals. 

5. Documentation & Continuous Improvement - Our deliverables go beyond the LOPA worksheet; we provide clear summaries, visual risk maps, and actionable recommendations that integrate seamlessly with your MOC and PSM systems. 

Achieving Simple Results for Safer Ops 

When done right, LOPA revalidation strengthens both compliance and culture. It ensures your team understands why each IPL exists and how they reduce risk.  The process excels in creating ownership and awareness that prevent incidents before they start. 

At McMillen Process Safety, we make revalidation a valuable exercise in risk clarity. We translate technical analysis into actionable insights that empower your team to operate with confidence. 

Allow McMillen Process Safety to assist your team and deliver Simple Results For Safer Ops by connecting with us!