BowTieXP is a risk assessment software tool that is based on the Bowtie method. A bowtie diagram visualises the risk that is being dealt with in one understandable picture. The diagram is shaped like a bowtie, creating a clear differentiation between the proactive and reactive side of risk management. In BowTieXP, the bowtie diagram provides an overview of multiple plausible incident scenarios and shows the barriers in place to control these scenarios.

Quintessa used the bowtie analysis for visualising and communicating risks and the steps taken to manage them in the sub-surface risk assessment for the Endurance CO2 store of the White Rose project. The Bowtie method was particularly helpful in communicating key risks in a complementary manner to the decision trees developed in TESLA. The Bowtie methodology also provided an important contribution to financial project planning by representing the active measures that may need to be taken in the future, thus helping to communicate the rationale for financial provisions.

Quintessa built a checklist of risks, preventative measures, mitigations and impacts for the North Sea Transition Authority (formerly the Oil and Gas Authority) to assist the NSTA Carbon Storage Licence stewardship. The structure of the main risk checklist was designed to broadly align with the Bowtie methodology. Such approach enabled understandable representation of the impacts of a hazard, the risk it presents, the controls preventing the event from occurring and the mitigation measures in place to limit the consequences.

The use of BowTieXP in addition to other tools is part of our commitment to use the 'right tool for the right job' and reflect specific client needs in the risk assessment area.

A bowtie diagram. In the top-centre of the diagram is a black and yellow striped box labelled ‘Hazard’. Vertically below, and connected to the hazard by a line, is a red and orange shaded circle labelled ‘Top event’, representing the moment control over the hazard is lost. On the left- and right-hand sides of the top event are blue boxes labelled ‘Threat 1’ and ‘Threat 2’, which cause the top event, and red boxes labelled ‘Consequence 1’ and ‘Consequence 2’, which result from the top event, respectively. The threats and consequences are all connected by lines, meeting at the top event to form a bowtie shape. Each of these lines are intersected by black rectangles, each labelled ‘Barrier’, and representing mitigation measures.

Figure 1: Example of bowtie diagram.