The different parts that make up this risk assessment model
One of the main strengths of the bowtie is the ease with which it may be understood and interpreted once the reader has a basic understanding of what the diagram elements represent and how they interact.
The bowtie model and the process by which it is put together follows eight basic steps.
It is worth noting that the Bowtie terminology differs slightly from Safety Management Systems, for example the term ‘Hazard’. How the terminology is linked between bowtie and SMS is detailed in the section called Implementing bowtie into Safety Management Systems.
|Hazard||Step 1 to build the bowtie focusing on aspects with the potential to cause injuries, damage or loss|
|Top Event||Step 2 which describes the undesired system state|
|Threats||Step 3 showing possible direct causes|
|Consequences||Step 4 in building the bowtie showing possible direct outcomes resulting in loss or damage|
|Prevention Controls||Step 5 to the bowtie to add any measures taken to prevent the threat and top event|
|Recovery Controls||Step 6 to the bowtie to add any measures taken to prevent the consequences|
|Escalation Factors||Step 7 showing a condition that affects the performance of the controls in place|
|Escalation Factor Controls||Step 8 is adding any measure taken to prevent the escalation factors impacting the controls|