Aviation Safety Management Systems Risk Assessment Additional Considerations

Posted by on
  • Hits: 46

Sofema Online (SOL) www.sofemaonline.com considers the key relationship between Root Cause and Contributing Factors in Risk Assessment

Introduction

In Root Cause Analysis (RCA), distinguishing between the Root Cause and Contributing Factors is crucial for implementing effective, targeted solutions. Addressing only contributing factors often leads to short-term fixes, while resolving the root cause eliminates the fundamental issue, leading to systemic improvement.

Root Causes are the deep, systemic drivers of failures, whereas Contributing Factors amplify or worsen risk without being the ultimate trigger. Addressing both is essential: root causes for sustainable safety improvements and contributing factors for short-term risk mitigation. Tools like Fishbone Diagrams, 5 Whys, and Fault Tree Analysis help organizations differentiate between these two, ensuring resources are directed effectively for long-term resilience and immediate safety enhancement.

Notes  

• Eliminating a root cause entirely prevents the recurrence of the problem. In contrast, addressing contributing factors reduces the likelihood or severity of the problem but does not eliminate it completely.

• Solutions that address root causes tend to be long-term and sustainable. On the other hand, tackling contributing factors often results in short-term or temporary improvements.

Root Cause – Definition - The underlying issue or failure that, if eliminated, would prevent the problem from recurring.

Key Characteristics:

• Fundamental and systemic.

• Exists deeper within organizational processes, systems, or culture.

• Often hidden, requiring thorough investigation to uncover.

• Eliminating the root cause removes the problem permanently.

Example:

• Issue: A runway incursion occurred.

• Root Cause: Outdated or unclear taxiway procedures in the Standard Operating Procedures (SOPs).

>> Fixing this ensures the root problem (misunderstanding or procedural ambiguity) is eliminated for all crews.

Contributing Factors - Definition - Elements that increase the likelihood or severity of a hazard occurring but are not the fundamental reason for the event.

Key Characteristics:

• Secondary in nature.

• Often external or situational.

• Eliminating contributing factors reduces the risk exposure, but the root problem can still trigger future events.

Example:

>> Issue: A runway incursion occurred.

>> Contributing Factors:

• Poor visibility due to fog.

• Fatigue among ground staff working extended shifts.

• High workload on Air Traffic Control (ATC).

Tools to Differentiate Root Causes and Contributing Factors

5 Whys Technique:

• Ask “Why?” repeatedly to trace causal links back to the root cause.

• Stops at the point where eliminating the cause prevents recurrence.

• Example:

>> Problem: Engine oil leak.

>> Why 1: The gasket failed.

>> Why 2: Incorrect torque applied during installation.

>> Why 3: SOPs did not specify proper torque values. (Root Cause)

• Contributing Factors: Operator fatigue and poor lighting in the workspace.

Fishbone Diagram (Ishikawa):

>> Organizes causes into categories (Man, Machine, Method, Environment, Material).

>> Helps visualize which factors are root causes and which are contributing.

>> Root Cause: Faulty SOPs under the “Method” category.

>> Contributing Factors: Human fatigue is under the “Man” category, and poor tools are under “Machine.”

Fault Tree Analysis (FTA):

• Works top-down to identify all pathways leading to the problem.

• Root Cause: The final, lowest-level cause in the tree that eliminates recurrence.

• Contributing Factors: Branches that may increase failure likelihood.

Examples to Clarify Root Cause vs. Contributing Factors

Scenario 1: Aircraft Ground Collision - Problem: Aircraft collided with ground equipment during pushback.

Root Cause: Lack of clear SOPs for pushback operations (systemic failure).

Contributing Factors:

• Ground crew fatigue from extended shifts.

• Poor communication between the cockpit and ground team.

• Low visibility due to lighting conditions.

Scenario 2: Engine Failure In-Flight - Problem: Engine failed mid-flight.

• Root Cause: Undetected wear due to insufficient inspection intervals.

• Contributing Factors:

>> High vibration due to poor weather.

>> Missed warning signals during pre-flight checks.

>> Short staffing in maintenance crews.

Why Address Both Root Cause & Contributing Factors

Root Cause:

• Essential for long-term solutions.

• Eliminating root causes prevents the recurrence of the problem, strengthening systemic resilience.

Contributing Factors:

• Reducing these enhances short-term safety and lowers immediate risk exposure.

• Examples include:

>> Fatigue management programs.

>> Improved communication tools.

>> Additional environmental controls (e.g., better lighting).

Example Strategy:

• While fixing the root cause of SOP issues (long-term), the organization implements immediate fatigue controls and enhanced communication protocols to reduce current risk.

Employee Engagement, Reporting Culture & Feedback Loops

• Foster a Just Culture to encourage hazard reporting without fear of blame. Ensure employees feel their reports lead to meaningful actions.

• Develop anonymous reporting systems to capture deep-rooted hazards that may not be voluntarily shared.

• Assess organizational culture for latent errors or misaligned priorities (e.g., production pressures overshadowing safety goals).

• Evaluate management's role in supporting SMS processes and hazard identification efforts.

• Implement Key Performance Indicators (KPIs) and performance audits to measure the effectiveness of safety measures and identify gaps.

• Regularly review hazard identification tools, processes, and systems to adapt to changes.

Prioritization of Risks - Rank risks based on Risk Tolerability:

• Intolerable Risks: Require immediate corrective actions to eliminate or reduce exposure.

• Tolerable Risks: Apply mitigations to reduce risk to an ALARP level (As Low As Reasonably Practicable).

• Acceptable Risks: Monitor regularly for changes in likelihood or severity.

• Use of Key Performance Indicators (KPIs):

>> Track recurring trends in high-risk areas using measurable KPIs.

Example: An increase in engine-related near-miss incidents over a quarter may indicate a systemic issue.

Residual Risk Management - Assess the effectiveness of existing controls after mitigation:

• Determine the residual risk level post-implementation of control measures.

Example: After adding redundancy in procedures, re-evaluate the risk matrix score.

Human and Organizational Factors - Incorporate Human Factors into Risk Assessment:

• Assess fatigue, workload, miscommunication, and cultural influences as contributors to risks.

• Evaluate systemic weaknesses, such as poor procedures or inadequate resource allocation, that amplify risk exposure.

Next Steps

Sofema Aviation Services and Sofema Online provide classroom, webinar and online training – SMS Hazard Identification & Risk Assessment - 1 Day

For comments & questions please email [email protected].

Rate this blog entry:
0