Alex de Ruijter

Alex de Ruijter

I develop concepts around, and train people in, barrier based risk management.

📍 Leiden

Writing too many procedures

James Reason's classic book Managing the Risks of Organizational Accidents has a lot of great risk management insights. Here are three paragraphs on adding too many procedures over time (p. 49): All organizations suffer a tension between the natural variability of human behaviour and the system's needs for a high

It's not enough to have safety barriers

The best definition of a safety barrier can be found in an article by Sklet from 2006: Safety barriers are physical and/or non-physical means planned to prevent, control, or mitigate undesired events or accidents. This definition has an interesting word. Planned. It implies that besides stopping unwanted events, a

The safety barrier definition

* Sklet, S. (2006). Safety barriers: Definition, classification, and performance. Journal of Loss Prevention in the Process Industries, 19(5), 494–506.

Use criticality to find important barriers

Which risk barriers are the most important? This question can be answered with barrier criticality. In this article we discuss why & how to approach barrier criticality as well as some challenges.

Practical applications of bowtie

It can be a challenge to know what to use bowties for. In this webinar we show different practical applications of bowties. From risk communication to barrier monitoring and decision support.

5 reasons why analysing barrier failures is better than 5-why

I hope you'll forgive me, but I don't really like 5-why. It's a decent methodology, but I think there are better options. Instead, we can use barrier-based incident analysis methods. Why is this better? Well, here are 5 reasons why I think analysing barrier failures is better than 5-why.

Why threats in bowties don't always lead to all consequences

In theory all threats in a bowtie diagram can cause the top event, and the top event can cause all consequences. But sometimes a threat can't lead to all consequences. Why is that and is it a problem?

The barrier maturity model

Many organisations have adopted the idea of barrier management in safety. Many are also searching for ways to take a next step. With the barrier maturity model you can determine where your organisation currently is and see which steps can be taken to mature to a higher level of barrier management.

An alternative to the hierarchy of control

The hierarchy of control is often used as a brainstorming tool to come up with effective controls (aka, barriers). It's good because it favours proactive interventions like eliminating a source of fuel over reactive interventions like putting out a fire. However sometimes it is misused as a formal classification tool.

Barrier states

A barrier can have different states in an incident, mostly divided into four types: 1) Missing barriers 2) Failed barriers 3) Inadequate barriers and 4) Effective barriers. There are considerable differences in interpretation of these states, and when one or the other should be used. Here I'd like to give