Notes on Bowtie Analysis & Control Assurance Management System (CAMS)

CIVL4170: Risk Analysis in Civil Engineering Notes

Risk Management Process and Overview

• Risk Management Process:
  • **Risk Treatment:
  • Unwanted Event Identification
  • Control Analysis and Selection
  • Control Management and Evaluation
  • Risk Assessment:
  • Establish the Context
  • Risk Identification
  • Risk Analysis
  • Risk Evaluation
  • Communication and Consultation
  • Monitoring and Review
  • ISO31000 framework and principles
  • Extended methods to identify hazards:
  • HAZID, RISK MATRIX, and TOLERABLE/ALARP assessment.

Bowtie Analysis

• Definition:
  • A Bowtie is a risk assessment tool that visualizes the relationship between threats and consequences of an unwanted event.
• **Components:
  • Hazard:** Something with the ability to cause harm (e.g., pressure, heat).
  • Threats: Events that could release that hazard (poor design, improper operation).
• Purpose of Bowtie:
  • Captures all elements of an unwanted event for better communication and management.
• Structure of a Bowtie Diagram:
  • The diagram includes threats on the left leading to the hazard, which has consequences on the right.

Controls and Control Assurance Management System (CAMS)

• Controls:
  • Measures that prevent unwanted events or mitigate their consequences to acceptable levels.
  • Can be objects or human actions.
• Types of Controls:
  • Prevention Controls: Prevent exposure to threats.
  • Mitigating Controls: Respond to consequences to reduce severity.
• Control Assurance Management System (CAMS):
  • A systematic approach to ensure the effectiveness of controls over time through monitoring and maintenance.
  • Core activities include monitoring, maintaining, and improving controls.
  • Erosion Factors: Performance of controls can diminish over time due to various factors such as wear and tear, human error,
    environmental conditions.

Steps to Conducting a Bowtie Analysis

1. Identify Unwanted Event:
   • Example: Unexpected change in the sewer atmosphere.
2. Determine Scope of Analysis:
   • Define people, locations, equipment, and activities involved.
3. Identify Threats:
   • Specific to the unwanted event (e.g., inadequate engineering, equipment failure).
4. Identify Consequences:
   • Potential outcomes arising from the unwanted event (e.g., harm to human health, environmental damage).
5. Select Controls:
   • Devices or actions to prevent or mitigate the unwanted event.
6. Develop CAMS:
   • Ensure the implementation and effectiveness of chosen controls.

Guidelines for Identifying Threats and Consequences

• Specificity is Key: Avoid general descriptions; be precise when categorizing threats and consequences.
• Focus on Solutions: Address underlying issues causing human error rather than blaming individuals.

Hierarchy of Risk Treatment Options

• Increasing Effectiveness:
  • Eliminate hazardous conditions
  • Substitute with safer options
  • Isolate and reduce exposure occurrences
  • Implement controls that reduce likelihood and mitigate consequences.

Critical Controls

• Definition:
  • These are controls that are essential to preventing or mitigating risks. Their absence significantly increases risk.
  • Effective controls should classify under various dimensions and be audited regularly for efficacy.

Example: Gravity Sewer Maintenance

• Key Risks Identified:
  • Unexpected atmosphere changes in the sewer system leading to catastrophic events.
• Tasks Required:
  • Analysis should include understanding threats and potential consequences, quickly identifying responsive controls, and implementing CAMS for continuous effectiveness.

Conclusion

• The Bowtie analysis alongside CAMS offers a clear, structured approach for understanding and managing complex risks in civil engineering projects.
• Regular monitoring and updates are necessary to ensure the long-term resilience and effectiveness of these risk management strategies.