Article Text

Download PDFPDF

6F.003 Prevention is not enough
  1. Vallorie Hodges1,
  2. Fiona McCarthy1,
  3. Ivan Pupulidy2,
  4. Professor Sidney Dekker3,4,
  5. Crista Vesel5
  1. 1University of Tasmania, Hobart, Australia
  2. 2Advanced Safety Engineering and Management University of Alabama at Birmingham, Sante Fe, USA
  3. 3Safety Science Innovation Lab Griffith University, Nathan, Australia
  4. 4Delft University of Technology, Delft, Netherlands
  5. 5Dynamic Inquiry LLC, Santa Fe, USA


A strong prevention bias in safety thinking doesn’t offer a robust understanding of the complexity of high consequence events. Despite the best risk assessments, procedures, and people, we simply cannot prevent all incidents. We must instead balance prevention efforts with capacity to respond and recover when things go badly. But how do we promote this concept within our operations?

This session offers a model we are using as a simple visual framework to stimulate dialogue and promote learning, shared understanding and safety differently language. The model is an adaptation of the bow-tie as a propeller. It includes preventive, operational and recovery elements placed in a dynamic mode, represented by turning blades – within a margin of manoeuvre sphere.

On one side of the bow-tie, prevention efforts deter threats, while on the other side capacity to respond to events reduces impact. The centre represents operational activity and an event moment. This is also the moment when workers recognize anomaly and make sense of the information, learn in the moment, and innovate a change to the system.

The bow-tie is depicted inside a sphere of influence representing margin of manoeuvre. Positive influences create outward force, maintaining a buoyant sphere. Negative influences put pressure on the system, reduce its size, robustness and even collapse it. An unbalanced bow-tie can also collapse the system.

When we conceptually shift from bow-tie to propeller, the model becomes dynamic, demonstrating how learning creates a feedback loop to improve the entire system- including preventive, operational and response/recovery components.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.