A bowtie is a diagram that visualizes the risk you are dealing with in just one, easy to understand the picture. The diagram is shaped like a bow-tie, creating a clear differentiation between proactive and reactive risk management. The power of a BowTieXP diagram is that it gives you an overview of multiple plausible scenarios, in a single picture. In short, it provides a simple, visual explanation of a risk that would be much more difficult to explain otherwise.
[[Image:Bowtie_Diagram.png|frame|c|right|An example of a bowtie diagramm.]]
== Hazard ==
The start of any
Bowtie is the Hazard. A Hazard is something in, around or part of the organization which has the potential to cause damage. Working with hazardous substances, driving a car or storing sensitive data are for instance hazardous aspects of an organization , while reading this article on your computer is not. The idea of a Hazard is to find the things that are part of your organization and could have a negative impact if control over that aspect is lost. They should be formulated as normal aspects of the organization. The rest of the Bowtie is devoted to how we keep that normal but hazardous aspect from turning into something unwanted. The first step is always the hardest , and this is also the case here. Normally, starting with for instance a HAZID is a good way to get a long list of all possible Hazards. Bowties are then done only for those Hazards with a high potential to cause extensive harm. Normally, 5 to 10 Hazards is a good starting point.
== Top event ==
Hazard is chosen, the next step is to define the Top Event. This is the moment when control is lost over the Hazard. There is no damage or negative impact yet, but it is imminent. This means that the Top Event is chosen just before events start causing actual damage. The Top Event is a choice though, what is the exact moment that control is lost? This is to a large extent a subjective and pragmatic choice. Often, the Top Event is reformulated after the rest of the Bowtie is finished. Don’t worry too much at the beginning about formulation. You can start with a generic “Loss of control” and revisit it a couple of times during the Bowtie process to sharpen the formulation.
== Threats ==
Threats are whatever will cause your
Top Event. There can be multiple Threats. Try to avoid generic formulations like “Human error”, “Equipment failure” or “Weather conditions”. What does a person actually do to cause the Top Event? Which piece of equipment? What kind of weather or what does the weather impact? You can be too specific as well, but generally people tend to be too generic.
== Consequences ==
Consequences are the result from the
Top Event. There can be more than one Consequence for every Top Event. As with the Threats, people tend to focus on generic categories instead of describing specific events. Try not to focus on Injury/fatality, Asset damage, Environmental damage, Reputation damage or Financial damage. Those are broader categories of damage rather than specific Consequence event descriptions. Try to describe events like “Car roll over”, “Oil spill into sea” or “Toxic cloud forms”. Besides containing more specific information, you’re also helping yourself to think more specifically when coming up with Barriers. Think how you want to prevent “Environmental damage” versus “Oil spill into sea”. The second is an actual scenario which makes it much easier to come up with specific Barriers.