The application of the Bow Tie approach in the risk assessment of a municipal solid waste management system

Effective municipal solid waste management requires rigorous risk assessment, evaluation and monitoring through a risk management system. In this line, this study aims first to highlight the importance of using the Bow Tie risk analysis method as a quantitative analysis tool for optimal waste management, and second to demonstrate the fact that the reliability of the method’s results, depends entirely on the uncertainty inherent in the various estimates of the stakeholders. Methodologically the work is based on two pillars: first, a study of the existing literature on risk management in the context of waste management is undertaken, and second, a bow-tie type risk analysis model is developed. Towards this end, and building on previous work, we concentrate on the highest impact event / hazard, identified in the existing municipal waste management system of the Municipality of Patra, Greece, and we apply the Bow Tie type analysis method in order to re-estimate its risk. This method’s results are then subjected to statistical and sensitivity analysis using Monte Carlo simulation to ensure the reliability of the results. Overall, the impacts of the most important risk are presented, and the advantages of the method are highlighted.