Root cause analysis (RCA) refers to a variety of problem-solving methods that attempt to identify and correct a problem's root causes. It assumes that the best way to solve problems is by eliminating their root causes. It also works under the belief that addressing obvious symptoms only serves as a short-term solution and does not prevent the problem from happening again.
Root cause analysis has been applied across industry sectors and disciplines. Safety engineers have used it to conduct accident analysis; production and maintenance engineers have used it to investigate failures in manufacturing. RCA has also emerged within change management, risk management, systems analysis, and other areas of business.
The process involves defining the problem, investigating through gathering evidence, identifying root causes, implementing solutions and, finally, monitoring those solutions to ensure they continue to prevent the original problem.
At its most basic, the process asks three questions, which together provide the framework of an Root cause analysis investigation:
1. What was the problem?
2. What were the causes of the problem?
3. What actions should be taken to prevent the problem from occurring again?
Root cause analysis can use a variety of techniques to uncover root causes, including Cause Mapping, change analysis, the Ishikawa fishbone diagram, 5 Whys, and others. All are designed to analyze the elements affecting a particular outcome to determine the root causes. Factors could include problems with materials, machines and equipment, environmental factors, management, methods and procedures.
Regardless of the specific technique, Root cause analysis investigations share certain common attributes.
- Every cause uncovered by RCA must be backed up by evidence.
- RCA usually uncovers a system of root causes. There is rarely one, singular root cause. Equipment may experience downtime due to a part failure. But why did the part fail? It could be a combination of part design problems, machine overuse and improper machine maintenance.
- RCA uncovers specific causes and effects. For instance, RCA does not stop with problems such as “human error.” Instead, it goes beyond this by asking what exact error was committed and why it happened.
- RCA results in executable, quantifiable solutions that may be monitored.
- RCA does not point blame at any one person or group, but simply identifies a system of causes and effects that lead to an incident.
- RCA focuses on past events.