Session: 07-03-03 Risk Management

Paper Number: 87280

87280 - Systematic Assessment of Risk Control Effectiveness 

The concepts of the Bow-tie approach and Swiss Cheese model are not new and are two key risk management concepts that that many organizations consider within their risk management practices.  The Bowtie Model provides a simplified representation of how multiple hazards can combine to create or cause an accident / risk event and that the event may result in multiple types of harm (or impact), i.e., safety, environmental, asset, financial.  The Swiss Cheese Model builds on the concept outlined in the Bowtie model.  Where the Bow Tie Model represents multiple hazards contributing to an event, the Swiss Cheese Model focuses on each hazard and the controls that are in place to prevent the hazard from causing an event or to mitigate the consequences if the event were to occur. As per the Swiss Cheese Model, adding layers of protection significantly increases the level of protection. Therefore, understanding the number of independent layers protecting against a hazard is important in determining the total barrier strength.  

Organizations spend much time identifying their hazards and assessing their risks, applying the many controls they may have in place to prevent undesirable events and outcomes.  When applying controls, they often consider a single control, do not consider how controls interact (i.e., Swiss Cheese Model) or make assumptions on how effective a control is at mitigating the risks identified.  Often times, the true effectiveness of barriers is not fully understood until an incident has happened or near miss events have occurred. Barriers are never perfect, and even the best hardware barriers can fail. Given this, to truly understand our risks, we need to pro-actively measure the effectiveness of controls to identify any barrier decaying mechanism factors (anything that may lead to the failure of a barrier).

Trans-Northern Pipelines Inc (TNPI) has embarked on a journey to better understand its hazards, risk events, and how well its current controls prevent hazards and mitigate the consequences of its most critical risk events.  This Safety Critical Element (SCE) Assessment was developed to support the systematic evaluation of the effectiveness of TNPI’s most important controls and to improve the overall quality of their Risk Management Process outputs. 

SCE Assessment Protocols have been developed to gather both quantitative and qualitative performance information regarding the components that make up each SCE.  There are assurance and verification activities happening regularly within organizations related to the critical SCEs (maintenance, inspections, assessments etc.). A review of these activities along with supporting information such as KPIs, identified gaps, limitations or weaknesses of the SCE components is gathered and used to evaluate the effectiveness of the SCE.

After defining each SCE layer, assessment protocols were designed to evaluate the effectiveness of the SCE components in terms of Functionality, Availability, and Reliability (FAR) performance. Assessing these three performance criteria provides a critical and thorough evaluation of the SCE by pinpointing limitations, gaps in implementation, and known or apparent weaknesses of the SCE components or the SCE overall.

The SCE Assessments informs the Corporate Risk Framework and how this in turn influences TNPI’s planning processes to address any additional mitigations that may be required to reduce risks to within acceptable levels.    

This proposed paper will outline the approach undertaken, the benefits realized and provide a summary of the novel SCE analysis completed to assess the effectiveness and interaction of risk controls in place. 

Presenting Author: Shreya Ambasta Trans-Northern Pipelines Inc.

Presenting Author Biography: Shreya is a professional Chemical Engineer and Process Safety Team Lead at Trans-Northern PIpelines Inc. She practically applies her extensive experience in process safety, risk management, and incident investigations, developed within the oil and gas industry, to support TNPI in improving their risk management, planning, and proactive response activities. <br/><br/>She supports both the strategic and tactical elements of risk at TNPI. She champions and mentors the organization in common risk practices, establishing risk standards, guiding assessments as well as completing detailed root cause analysis that reduces the potential for recurrence of incidents.