Bowtie Analysis is used for risk assessment, risk management and risk communication.
By using bowtie diagram we can visualise risk. It shows the causes and consequences of an event. More over the control measures to mitigate the risk is also shown on the diagram.
Having potential causes and control barriers on one side and having potential outcomes and defense causes the other side of the hazardous event gives this analysis the shape of "Bow Tie". It simply combines Fault Tree (FT) and Event Tree (ET).
Bow-tie Shape reference
Bow-tie Modelling
Examples:
Factory Fire Bow-tie Example
Financial Product Bow-tie Example
Car Crash Bow-tie Example
Bow-tie use cases:
Risk Analysis
Reliability Engineering
Safety Assessment
Mining
FMEA use Cases:
Chemical
Aerospace
Military
Automobile
Electrical
Mechanical
Large scale industries
Difference between FMEA and Bowtie:
FMEA is Bottom-up and Bowtie can be constructed using both bottom-up and top-down approach
FMEA is quantitative whereas Bowtie is qualitative
In general, risk analysis helps an organization to identify risks and potential threats to its internal operational processes and provides severity and likelihood of those occurrences. Below is the list of risk analysis methods and techniques.
Qualitative:
Bowtie Analysis
Delphi Technique
SWIFT Analysis
Fly Analysis
Risk Register
Probability-Impact Matrix
Risk Categorisation
Expert Judgement
Quantitative:
Monte Carlo simulation
Decision Tree Analysis
Sensitivity Analysis
Three-Point Estimation
FMEA
Scenario Analysis
Latin Hyper Cube Simulation
Conclusion:
Even though there are many risk assessment methods like Bowtie, FTA, FMEA, etc., they focus with single threats and most of the time struggle to represent multiple simultaneous failures.
FMEA systematically identifies the effects/consequence of Failure mode and used to remove/reduce the possibilities of failure and Bowtie, predominantly gives hazard insights and its management and helps to represent the influence of safety system on the shop floor accident scenario.
Integrating them, both Bowtie and FMEA can be used together for hazard analysis and risk assessment. Detection rating and RPN calculation based on FMEA along with corrective measures to improvement RPN and subsequently using bowtie to identify safety critical barriers and associates actions can improve the effectiveness drastically.