Every business has legal, economical, and ethical objectives that range from mandatory safety to commercial goals to corporate citizenship. Businesses undertake a certain amount of risk to achieve these objectives. The balance between risk and reward is an ongoing challenge regardless of the activities involved. The bowtie technique can be used to visualize, assess, and manage risk.
By: David Hatch
Bowties offer the following advantages:
An alternative view on risk management could simply be "failure management." Failures often begin as threats that start a chain of undesirable events; they must be stopped or slowed by measures that themselves have the potential to fail.
New projects may be able to implement additional barriers. Established facilities may only be able to improve existing barriers. When resources are limited, management must be confident that they are investing in improvements (training, maintenance, inspection, etc.) that can deliver results.
The pharmaceutical industry is not unfamiliar with hazard and risk analysis tools and techniques. The most common, from ICH-Q9, are listed below.1
A more extensive list is available from the Center for Chemical Process Safety.5
All these methods have strengths and weaknesses, which are documented in a UK Health and Safety Laboratory research report.6 HAZOP, for example, is a widely used hazard-identification methodology; it is not effective in identifying where multiple cause can lead to the same consequence, however.
Bowtie analysis is not intended to replace existing tools and techniques, but to enhance them by helping those involved in the original identification or analysis studies to confirm their discussion, and those not involved in the studies (but still responsible for managing risk) to understand and address relevant issues.
One major limitation of most common techniques is that they are typically performed by specialists and documented in a technical language and format that does not easily support communication and ongoing collaboration. The UK Health and Safety Executive recognizes that a barrier (bowtie) approach is a useful tool in communicating major hazards information to the workforce.7
The clarity that bowties provide can also be used to validate existing studies more efficiently, e.g., to identify errors or omissions in the causes, effects, and control measures associated with particular scenarios. This is a key issue in high-hazard facilities that are mandated to revisit their PHA or HAZOP every five years under regulations such as the US Occupational Safety and Health Administration or the Seveso Directive.