TRIPOD BETA
Tripod Beta is a barrier-based incident investigation methodology developed by the Energy Institute and the Stichting Tripod Foundation. It is built on a simple but important idea: industry manages risk by putting barriers in place between a hazard and potential harm. When an incident happens, one or more of those barriers failed. Tripod Beta is the tool we use to find out which ones, why they failed, and what in the organisation allowed that to happen.
Three questions that drive every investigation
What happened?
The sequence of events
We map the context, the hazard, the event itself, what or who was affected, and what harm occurred or could have occurred.
How did it happen?
The failed barriers
Which controls or safeguards should have stopped or limited the event — and did not? This is the gap between how work is imagined and how it actually happened.
Why did it happen?
The root causes
For each failed barrier: what was the immediate cause, what job conditions made failure more likely, and what organisational factors created those conditions?
WHAT THIS LOOKS LIKE IN PRACTICE
- When an incident or near miss is investigated using Tripod Beta, we start by building a picture of what was happening just before the event. What task were you doing? What were the conditions? This is not about catching anyone out — it is about understanding the full situation.
- We then look at the barriers — the checks, procedures, inspections, or physical safeguards that should have been in place. We ask: were they there? Did they work? If a barrier failed, we want to understand what actually happened, not what the procedure says should have happened.
- We ask about the conditions you were working in. Were you under time pressure? Was the procedure clear and available? Was the workspace difficult? Were you interrupted? These are not excuses — they are data. They tell us what made the task harder than it should have been.
- Finally, we look at the bigger picture — what in the organisation created those conditions. Was it a training gap? A supervision issue? A procedure that does not reflect how the work is actually done? This is where lasting change comes from.
TYPES OF BARRIERS
- Passive physical defence
- Active automated process
- Human intervention
- Combined technology + human
JOBS FACTORS VS ORGANISATIONAL FACTORS
Job factors — what made your task harder
Fatigue, stress, time pressure, noise, poor lighting, an unclear procedure, an interrupted task, unfamiliar equipment. There are 31 defined categories covering people, environment, equipment and procedures.
Organisational factors — what created those conditions
Training and competence management, supervisory oversight, safety climate, resource allocation, clarity of responsibilities. 14 categories covering the systemic issues that sit behind the job factors.
Tripod Beta does not look for the person who made a mistake. It looks for the gaps in the system that made a mistake possible. If a barrier failed, that barrier needs to be fixed — not the person who happened to be standing behind it when it gave way. Your account of what the work actually looked like that day is the most honest source of information we have. Without it, we are only investigating a version of events that exists on paper.
Zdroje: Maintenance Event Decision Aid (MEDA) User's Guide©