From 1940s battlefield research to a construction site near you

OPALs didn’t come from nowhere. The method has serious roots.

The Critical Incident Technique was developed by psychologist Paul Fitts in the 1940s — originally applied to battlefield leadership — and formalised by John Flanagan in his influential 1954 paper of the same name. Decades later, the System Safety Development Center (SSDC) in the US adapted it for occupational safety at nuclear sites, renaming it the Reported Significant Observation (RSO) study. I encountered it there as a PhD student. Bob Nertney, one of the original SSDC team, impressed on me just how central it was to their work — not only as a way of learning from the workforce, but as a tool for building and validating a model safety management system applicable across America’s varied nuclear sites.

OPALs applies that same logic to construction. But it has a second strand, aimed at managers, that we’ve found harder to get off the ground.

The frontline sessions produce something valuable: an authoritative picture of what precautions are needed and, crucially, what conditions make them work reliably. Managers create most of those conditions. So the parallel question for them is: how do you make this happen? The method follows the same structure — precaution by precaution, drawing on first-hand experience. One manager described a trench box that ended up concreted into the ground because the method statement said nothing about removing it. The lesson: handing that task to a newly qualified engineer, without experienced oversight, is a risk in itself.

Getting managers into the room, and keeping them there, has proved difficult. Construction firms are busy. That’s a problem we’re still working on.

OPALs is not limited to construction. The underlying logic applies wherever frontline workers do physical work with real consequences — and wherever managers make the decisions that shape whether safety measures actually hold. We have made a promising start with the frontline strand. The management strand is where the real development work remains, and we are looking for an industrial partner willing to explore it with us. This is not a consultancy pitch: we are looking for an organisation that wants to be part of building something, in return for covering our time and expenses. If you lead safety in a large construction firm — or another industry where this resonates — we would genuinely like to hear from you.From 1940s battlefield research to a construction site near you