Friday, July 9, 2021

Make An Effective Root Cause Analysis

 Make An Effective Root Cause Analysis

By Catalina9

Within an aviation safety management system, a root analysis should be conducted of special cause variations which caused an incident. The two types of variations are the common cause variations and special cause variations. A common cause variation exists within the system itself as an inherent risk and is to be mitigated by applying a risk analysis of a probability exposure level upon arrival at location, direction, or time. Bird migration and seasonal airframe icing are examples of common cause variations. Special cause variations do not exist within the process itself but are interruptions to a process by external forces. Birds or wildlife on the runway, or icy runway are special cause variations, since they are beyond airport certification requirements, and the airport operator is expected to maintain a bird and wildlife free runway environment and a contamination free movement area. However, for an airport operator both bird and wildlife and ice contamination are common cause variations to which they should apply an expected exposure level upon arrival of an aircraft.

The two most common root cause analysis processes are the 5-Why-s and the Fishbone. The fishbone analysis is a visual analysis, while the 5-Why-s is a matrix. Preferred method is defined in the Enterprise’s SMS manual. A root cause output, or corrective actions required, will vary with the type of analysis used and the subjectivity of the person conduction the analysis. The first step in a root cause analysis is to determine if a root cause is required and why it is required. A risk level matrix should identify when a root cause is needed. A root cause analysis should be conducted for special cause variations. However, the risk level of a special cause should be the determining factor for the analysis. For a risk matrix to be both objective and effective, it must define the immediate reaction upon notification, identify when a root cause analysis is needed and define both the risk levels when an investigation is required, and at what acceptable risk level an investigation is conducted.

When conducting a root cause analysis there are four factors to be considered. The first factor is human factors, the second is supervision factors, the third is organizational factors and the fourth is environmental factors. Environmental factors are categorized into three sub-factors, which are the climate (comfort), design (workstation) and culture (expectations). Culture is different than organizational factors in that these are expectations applied to time, location, or direction. Example: A client expect a task to be completed at a specific time at an expected location with direction of movement after the task is completed. Organizational factors are how the organizational policies are commitments to the internal organization in an enterprise and the accountable executive’s commitment.


There is only one root cause,
but several options for selection
  A principle of the safety management system is   continuous, or incremental safety improvements and   an accurate root cause sets the stage for moving   safety forward. The very first step in a root cause   analysis is to identify the correct finding. This might   be a regulatory non-compliance finding, an internal   policy finding, or a process finding. The root cause   analysis for a regulatory non-compliance finding is   an  analysis of how a regulation was missed, or how   an enterprise drifted away from the regulatory   requirement. An example of regulatory non-   compliance is when an enterprise drifts away from   making personnel aware of their responsibilities   within a safety management system. The root cause is then applied to the accountable executive level, who is responsible for operations or activities authorized under the certificate and accountable for meeting the regulatory requirements. The root cause for an internal policy finding is when the safety policy becomes incidental and reactive to events occurrences, rather than a forward-looking policy, organizational guidance maternal for operational policies and processes, a road map with a vision of an end-result. A sign of a safety policy in distress, or a system in distress, is when policy changes are driven by past events, opinions, or social media triggers, rather than future expectations. An internal policy root cause is applied to the management level in an enterprise. The most common root cause analysis is a process finding root cause. This root cause analysis is applied to the operational level. An example could be a runway excursion. With a runway excursion both the airport and airline are required to conduct a root cause analysis of their processes.
The root cause is your compass.

A root cause analysis is to backtrack the process from the point of impact to a point where a different action may have caused a different outcome. A five columns root cause matrix should be applied to the analysis. Justifications for five columns analysis is to populate the root cause matrix with multiple scenarios questions rather than one scenario that funnels into a root cause answer. The beauty of a five-column root cause analysis is that answers from any of the column may be applied to the final root cause, and if it later is determined to be an incorrect root cause, the answers to the new root cause analysis is already populated in the matrix. When the root cause is assigned, it should be stated in one sentence only. It is easy to fall into a trap assigning the root cause to what was not done. However, since time did not stop and something was done, the root cause must be assigned to what was done prior to the occurrence. An example of an ineffective root cause would be that the pilot did not conduct a weight and balance prior to takeoff. In the old days of flying, the weight and balance of a float plane was to analyze the depth and balance of the floats. Airplanes flew without incidents for years using this method. For several years standard weights were applied to personnel and luggage. Applying the standard weight process is similar to applying the float analysis process. Aircraft flew without incidents for years applying guestimates of weight rather than actual weight. At the end of the day, the fuel burn became the tool to confirm if correct or incorrect weight was applied. That a weight and balance was not done is not the root cause. The root cause could be one or a combination of human factors, organizational factors, supervision factors or environmental factors. The next step in a root cause analysis is to analyze these factors to assign a weight score to the root cause factor. 

A weight score is applied to human factors, organizational factors, supervision factors and environmental factors by asking the 5-W’s + How.  Examples of considerations are shown below.


When the root cause has been decided, but prior to the implementation phase of the corrective action plan (CAP), apply a link to the safety policy via objectives and goals by a process design flowchart of the expected outcome. This flowchart is your monitoring and followup document of the CAP for each step defined in the process. 


Catalina9








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