Research Articles

Basic Elements of Root Cause Analysis

Basic Elements of Root Cause Analysis (RCA) has the conundrum of being seen as the same as problem solving of crisis management.  The practice of RCA is predicated on the belief that problems are best solved by attempting to address, correct or eliminate root causes, as opposed to merely addressing the immediately obvious symptoms. By directing corrective measures at root causes, it is more probable that problem recurrence will be prevented. However, it is recognized that complete prevention of recurrence by one corrective action is not always possible.

As we perform quality assurance, we follow steps outlined in the process improvement plan to identify areas of improvement. This analysis also examines problems and constraints experienced, and non-value activities identified during work execution. Process analysis includes root cause analysis used as a specific technique to identify a problem, discover the underlying causes that lead to it, and develop preventive actions. In this context root cause analysis is used not only to identify where corrective action needs to be taken but also opportunities for process improvement.

Project risk management root cause analysis is a specific technique used to identify project risks. Remember that the PMBOK® definition of risk includes opportunities as well as threats. In both quantitative and qualitative risk analysis root cause is used to provide valuable input into the risk response plan. Again in this context root cause applies not only to potential problems or threats but also to positive risks or opportunities.

These two best practice sources show us that although RCA is typically used as a reactive method of identifying event causes, revealing problems and solving them. Analysis being done after the event has occurred. It can also be used in a proactive way. As a proactive method RCA can be used to forecast or predict probable events even before they occur.


Approaches to RCA

What are the various approaches to RCA?

RCA is not a single, sharply defined methodology. There are many different tools, processes, and philosophies for performing RCA. There are several broadly defined approaches that can be identified by their basic field of origin.

  • Safety based RCA descends from the field of accident analysis and occupational safety and health.
  • Production based RCA has its origins in the field of quality control for industrial engineering and manufacturing.
  • Process based RCA is basically a follow-on to production based RCA, but with a scope that has expanded to include business processes.
  • Failure based RCA is rooted in the practice of failure analysis as employed in systems engineering and maintenance.
  • Systems based RCA has emerged as an amalgamation of the preceding schools, along with ideas taken from fields such as change management, risk management, project management, and systems analysis.

Consider the situation when considering RCA.  The following situations would be successful candidates for RCA:

  1. Corrective Action
  2. Preventive Action
  3. Continuous Improvement


Reaching the Root Cause

How do I reach the root cause?

RCA assumes that systems and events are interrelated. Action in one area triggers an action in another, and another, and so on. By tracking these actions back you can discover where the problem started and how it grew into the symptoms you now face. There are usually three basic types of causes:

  1. Physical causes – tangible material items that have failed in some way. For example, a power source failure or a motherboard meltdown.
  2. Human causes – attributed to people that did something wrong or did not do something that was needed to be done. Human causes typically lead to physical causes. For example, a power source failure due to overloading of the power source.
  3. Organizational causes – some system, process, or policy that people use to make decisions or do their work is faulty. For example, a power source failure due a lengthy break between routine maintenance checks.

Root cause analysis looks at all three types of causes. It involves investigating the patterns of negative effects, finding hidden flaws in the system, and discovers specific actions that contribute to the problem. RCA often reveals more than one root cause.



Root cause analysis can help to transform a culture that reacts to problems into a forward-looking culture that solves problems before they occur or get out of control. More importantly it reduces the frequency of problems occurring over time within the environment where the RCA processes are used. As an analytical tool RCA is an essential way to perform a comprehensive, systematic review of problems, opportunities, and requirements.

The advantage of RCA is that it provides a structured method to identify the root cause of known problems thus ensuring a complete understanding of problems under review. The disadvantage is that RCA works best when someone who has formal training or extensive experience facilitates a team of experts. The primary concern revolves around the ability of the team to remain objective and open to critical analysis. Not using RCA correctly can lead to the illusion of problem solving without the benefits that RCA can provide.

Written by Jeffrey Stempien, PMP