Bowtie Risk Assessment

IEMA has significant experience in risk assessment having completed numerous complex risk projects across a range of operating conditions.  IEMA recently adopted the 'Bowtie' risk assessment methodology that allows great functionality and delivers leading risk assessment outcomes.

....  The strength of the methodology lies in its simplicity; the phrase “less is more” is certainly applicable......

Why use the Bow Tie Risk Assessment model?

The bowtie risk assessment model is increasingly being endorsed as a leading practice risk management by regulators and industries worldwide.  The bowtie diagram is a simple, yet effective visual tool to map the links between potential causes, preventative (proactive) and mitigative (reactive) controls and predicted consequences of unwanted events.

The bowtie diagrams are easy for stakeholders and employees at all levels of an organisation to read and understand and will improve the organisational effectiveness communicating the relationships between unwanted events, causes, controls and consequences.

Image by Dylan Gillis

Individual bowtie diagrams for specific ‘threat lines’ can easily be incorporated into management plans, procedures, and ‘tool-box’ training sessions to clearly depict the risks and controls associated with specific activities.

The Bow Tie Risk Assessment Model

The bowtie method is designed to give a better overview of the situation in which certain risks are present and help people understand the relationship between the risks and organisational events. 

Risk management is about controlling risks. This is done by implementing controls to prevent certain unwanted events from happening. A control can be any measure taken that acts against some undesirable force or intention, in order to maintain a desired state.  In bowtie methodology these are proactive barriers (on the left side of the top event) that prevent the unwanted event from happening (in this case failed rehabilitation).


There are also reactive barriers (on the right side of the top event) that prevent the event resulting in unwanted consequences. By identifying both the proactive and reactive controls there is a greater likelihood that the unwanted event will not occur, or (should it occur) minimise the adverse consequences. 

Summary of Key Projects

  • BowTie Risk Assessment for Rehabilitation and Mine Closure

  • Bowtie Risk Assessment & Failure Mode Effects Analysis (FMEA) for Tailings Dam

  • Review of critical controls identification for rehabilitation processes using Bowtie Risk Assessment Methodology

Leading Practice Risk Management

Industries that are exposed to catastrophic events (such as the aviation industry), and the associated industry regulators, are widely adopting the bowtie risk assessment model to assess risks associated with catastrophic or critical unwanted events. 

Regulatory bodies and organisations that adopt the bow tie risk assessment model include:

  • NSW Resources Regulator

  • UK Civil Aviation Authority

  • United States EPA

  • Heathrow Airport Limited

  • British Airways

  • BHP

  • Rio Tinto