To start, let’s define Root Cause Analysis (RCA) at the most basic level, and to do so, we will use industry standard sources and definitions from the ASQ and Wiki pages. The definitions have been enhanced and expanded upon by ThinkGRC. Our intent is to present the most important parts of RCA and frame the best approach.
Root Cause Analysis (RCA) is a method of problem solving used to identify the root cause(s) of negatively impacting events such as: problems, accidents, incidents, failures, deviations, or non-conformances. In short, if an event generates a negative impact (or potential), RCA is used to identify the root cause(s) and causal factor(s) (i.e. contributing factors) of the event and to identify actions to eliminate or mitigate the possibility of recurrence. The root cause is the issue/reason why the problem ultimately occurred/exists. RCA methodology contains both a reactive and proactive risk posture. RCA is a risk management tool which contains the fundamental core concept of risk elimination or mitigation through root cause identification. In practice, if you eliminate or effectively mitigate the root cause, the problem will be eliminated or will not occur again as originally stated within the problem statement.
In today’s business operations, most systems are rather complex and when an issue/incident occurs, there can be a multitude of variables that contribute to failures associated with the issue/incident. To address these complexities, Root Causes Analysis implements additional processes for identification of these variables commonly referred to as Causal Factors or Contributing Factors. Causal Factors can be thought of as catalysis or variables that also contribute or factor into the issue/incident but they are not the ultimate cause of our issue/incident. Causal Factors can affect the size and scope of an issue/incident, and should be incorporated into RCA methodology. In theory, identification and elimination of Causal Factors will (potentially) reduce impact, mitigate or reduce the likelihood of our issue/incident occurring but removal of a causal factor will not ultimately eliminate the issue/incident such as the root cause. The action of providing resolutions or mitigation of root cause(s) or causal factor(s) is commonly referred to as Corrective and Preventative Actions Management (CAPA).
What does all of this mean? This means that RCA is not a single dimensional tool focused on identifying the cause of an incident. RCA is a structured and comprehensive process of breaking down negatively impacting events to identify all aspects that contributed to the event such as causal factors and root causes and also identify the actions required to eliminate or mitigate the possibility of the event recurring.
Root Cause as a formal methodology has a rich history mainly developed within the maritime, aviation and process safety industries such as Oil & Gas and Chemical Manufacturing. Due to the vast development of RCA, there are a wide range of methodologies, tools and techniques that can be applied and we will discuss some of those in the next section.