Using bowtie analysis

The bowtie analysis process helps to understand, analyse and communicate risk scenarios to a broad audience. The output is a bow tie diagram which captures credible risk scenarios related to a specific hazard, and ways an organisation can stop those scenarios from happening. This involves analysing the risk to understand its size, nature and profile. For this reason we have produced a good practice guide to help industry as the use of bowties gradually increases.

There are several questions you should ask yourself before you start a bow tie analysis: 

• What are you trying to achieve?
• What is the problem you are trying to solve?
• How will you to use the bow tie model?
• Who is the intended audience for the bow tie model?

There may be different reasons for producing a bow tie model, some potential reasons for carrying out a bow tie risk analysis are:

• to demonstrate the level of control of a specific risk.
• to identify areas of safety management for improvement.
• to improve the quality and clarity in communicating a risk area to a wider audience.
• to provide a rich picture of a problem to facilitate discussion and identify further work.
• to understand the nature of a specific problem to improve its management.
• to provide a generic industry-level model to develop company or location specific bow ties.
• to provide a detailed audit tool as assurance of the effectiveness of existing controls.
• as an integrated tool in a company’s safety management system, linked to specific processes and procedures.
• to review the aspects of an incident to understand what went wrong and identify lessons and recommendations.

We have produced the Rail Industry Bowtie Analysis: A Good Practice Guide to provide an overview on the use of bow tie risk analysis as their usage increases in the rail industry. The goal is to improve understanding and management of safety risk through a clear and relatively concise description of what good practice looks like and encourage a consistent application of the methodology. 

Part 1 provides a background for bow tie analysis, where it comes from, when to use it.

Part 2 gives guidance on how to plan a bow tie analysis and highlights the importance of defining who will use the model, and what they will use it for.

Part 3 outlines the elements of a bow tie model and gives guidance on how to combine them to produce a model that will be suitable for your objectives.

Part 4 describes what to do with a bow tie model: how to use it, what to use it for, communicating risk, action planning, monitoring and review.