The Tripod Beta user guide
ISBN: 978 1 78725 361 2
Version: 6 (2023)
Tripod Beta: Guidance on using Tripod Beta in the investigation and analysis of incidents, accidents and business losses is the current manual on using the Tripod Beta methodology. This publication describes the Tripod Beta incident investigation and analysis methodology, giving step-by-step instruction and detailed guidance for both new and experienced users in the application of Tripod Beta. It is recommended reading for anyone looking to apply a consistent and robust incident and accident investigation and analysis methodology, particularly incident investigators, as well as those who have undergone training in Tripod Beta.
A Tripod Beta investigation has 3 stages:
1. What happened? This is where the timeline of the incident is established and the sequence of events are modelled as a 'trios'. Each trio represents how a hazard impacted on an 'object' and resulted in an event. This allows a non-linear representation of the incident to be created.
2. How did it happen? Next, the investigation asks what barriers (risk controls) should have been in place to prevent the hazards from impacting on the objects. Did these fail, were they effective, or were they missing?
3. Why did it happen? Lastly, the investigation find out what human actions or unsafe situations led to the barrier failures (the immediate causes), what were the psychological, environmental, or job factors that caused these situations (preconditions), and what were the organisational factors that influenced or created these (the underlying causes).
This short video provides an overview of the methodology: