Bowtie risk assessment for inspection authorities

The Enforcement Regulatory Cycle is extensively used to assist governmental agencies to manage the enforcement process and to develop inspection strategies. Risk-based inspection has been identified as the best practice for successful enforcement. The Bowtie methodology is a risk assessment method that can be used as a tool for risk communication and risk based inspections. Bowtie can be valuable in several stages of the Regulatory Cycle, such as Compliance Control, Compliance Promotion, and Assessment Feedback.

The Enforcement Regulatory Cycle and risk-based inspection

The enforcement process is crucial for the success of implementation and execution of (new) legislation. The Regulatory Cycle (figure 1) is extensively used to assist governmental agencies to manage the enforcement process and to develop inspection strategies.1

The success of enforcement depends largely on the effectiveness and efficiency of the inspection. Risk-based inspection has been identified as the best practice. In some fields risk-based inspections are already required in the legislation. For example, Art. 23 of Industrial Emission Directive2 specifies that environmental inspections should be based on environmental risks. As a part of planning of environmental inspections (inspection frequency) an easy and flexible risk assessment tool, EasyTools, has been developed by European Union Network for the Implementation and Enforcement of Environmental Law (IMPEL). However, knowing the inspection frequency and totally depending on various checklists, without being aware of the risks in the industry, has become a major problem for most Inspection Authorities. Increasing the focus on risk identification is needed for effective and high quality inspections.

Bowtie for risk-based inspection

The Bowtie methodology is a risk evaluation method that can be used to analyze and demonstrate causal relationships in high risk scenarios. The method takes its name from the shape of the diagram that you create, which looks like a men’s bowtie (figure 2)3.Bowtie for risk-based inspection

Bowtie takes out the complexity of methodologies like Fault trees and Event trees and uses barriers instead, making it an excellent tool for risk communication and risk based inspections.

Currently, the bowtie methodology is already used by the inspection authorities in several countries in various sectors to develop effective risk-based inspection strategy and planning. These authorities include the Petroleum Safety Authorities Norway (PSA), the UK Civil Aviation Authority (CAA)4 and the Dutch State Supervision of Mines (SSM)5.

The Accidental Risk Assessment Methodology for Industries (ARAMIS) also suggests using the bowtie methodology to identify the risk under Seveso II directive6,7.
The Bowtie methodology can be valuable in several stages of the Enforcement Regulatory Cycle, such as Compliance Control, Compliance Promotion, and Assessment Feedback.
An Inspection Authority is not able to inspect all existing safety measures. Compliance Control often focuses on a selection of critical safety aspects. Bowtie risk assessment can be used to identify which safety measures should be considered as critical, and thus can be used to develop inspection programs. Some examples have been given below.An assisting tool for Compliance Control

The Dutch State Supervision of Mines (SSM) has developed inspection programs for the next five years by looking at the risks shown in the bowties5. The frequently used barriers in the bowties will be supervised in separate inspection projects of the programs. Bowtie could be also a helpful tool to identify whether the right data is inspected during Compliance Control. For example, while creating Bowtie diagrams, the UK Civil Aviation Authority (CAA) found that they did not inspect certain data which is helpful for the assessment of barrier effectiveness4. The bowtie methodology hence can be used to identify the right questions that should be asked by inspectors during compliance control.

Further, Bowtie diagrams provide a direct link between risk scenarios and inspection results. Therefore, Bowtie gives an indication of the severity of the non-compliance in the inspection results. For example, multiple non-compliances in one single possible scenario should be rated as more severe than various non-compliances in different scenarios.
During 2013, the Petroleum Safety Authorities Norway (PSA) will clarify relationships between risk assessments, barrier strategies and barrier performance, and they will ensure that barrier performance is being monitored throughout the producing life of installations8.

ARAMIS recommends to use the Bowtie methodology to demonstrate that hazards are identified and risks are properly managed and to indicate what kind of safety barriers could (best practices) or must (compliancy) be implemented6,7.

A communication tool for Compliance Promotion

The bowtie diagram is perfectly suitable for communication. The diagram is easily understandable and ‘the picture paints a thousand words’. Inspectorates can use the diagram to communicate information to the industry. For example, in case of non-compliance, the inspectorate can use Bowtie diagrams to show the non-compliant organization which (mandatory) barriers have to be implemented or should be adjusted to achieve the level of compliance.

Also, when new legislation comes into force, Bowtie diagrams can be used to communicate and ‘promote’ the new legislation, by visualizing the new mandatory safety measures (figure 3).

A tool for sharing Best Practices

As a suggested extension of Compliance Promotion, Bowtie diagrams can be used for “Best Practice Promotion” (figure 3). Sharing best practices between Inspectorate and industry is evaluated as very useful by most organizations since this communication is more focused on collaboration between Inspectorate and industry, instead of giving or getting penalty due to non-compliance.

The Dutch State Supervision of Mines (SSM) is a good example of an inspectorate collaborating with the industry5. In 2012, SSM has started the development of bowties around the distribution of gas, working closely together with the industry. The SSM tries to help the gas network to get a better understanding on how to manage the major hazards relating to the distribution of gas. The insights from the bowtie diagrams have been very helpful for assisting the gas network operators with their safety programs.

Civil Aviation Authority (CAA), UK’s specialist aviation regulator, is another example of sharing best practices with the industry using bowties4. The CAA is developing Bowtie diagrams covering each of the CAA’s ‘significant seven’ safety issues. The shared goal of CAA and the industry is a balanced risk overview for the whole aviation system.

A tool for Structuring Assessment Feedback

The information derived from Compliance Control, Compliance Promotion and Enforcement need to be assessed. This information will need to be considered when improving the appropriate elements of the Regulatory Cycle. The Bowtie diagrams will provide an indication of industry-wide safety measurement performance when plotting all inspection results in the bowtie diagrams. Some elements of the cycle such as Regulations and Compliance Control can be improved based on the result of this safety measurement performance indication.

Further reading

  1. Putte, I. van der (2006). Chemicals In Our Environment. Practical implementation of risk-management strategies. AWE International June 2006.
  2. Directive 2010/75/EU of the European Parliament and of the Council. On industrial emissions (integrated pollution prevention and control) (2010).
  3. CGE Risk Management Solution (2013). BowTieXP Methodology Manual. Revision 13. Not published.
  4. CGE Risk Management Solutions (2012). Civil Aviation Authority develops BowTies for ‘Significant Seven’ Safety Issues. Not published.
  5. CGE Risk Management Solutions (2012). Analyzing barriers at the Dutch State Supervision of Mines. Not published.
  6. H.Andersen, J.Casal, A.Dandrieuxet, et. Al. (2004). ARAMIS: User guide. The European Commission. Community Research.
  7. Delvosalle, C., Fiévez, C., Pipart, A., Londiche, H., and Debray, B. (2004). ARAMIS Project: Effect of safety Systems on the Definition of Reference Accident Scenarios in SEVESO Establishments. The European Commission. Community Research.
  8. Petroleum Safety Authorities. Barriers.
2017-08-11T16:13:16+00:00 AuditXP, Blog, Compliance|