Root cause analysis

In science and engineering, root cause analysis (RCA) is a method of problem solving used for identifying the root causes of faults or problems.^[1] It is widely used in IT operations, manufacturing, telecommunications, industrial process control, accident analysis (e.g., in aviation,^[2] rail transport, or nuclear plants), medical diagnosis, the healthcare industry (e.g., for epidemiology), etc. Root cause analysis is a form of inductive inference (first create a theory, or root, based on empirical evidence, or causes) and deductive inference (test the theory, i.e., the underlying causal mechanisms, with empirical data).

RCA can be decomposed into four steps:

1. Identify and describe the problem clearly
2. Establish a timeline from the normal situation until the problem occurrence
3. Distinguish between the root cause and other causal factors (e.g., via event correlation)
4. Establish a causal graph between the root cause and the problem.

RCA generally serves as input to a remediation process whereby corrective actions are taken to prevent the problem from recurring. The name of this process varies between application domains. According to ISO/IEC 31010, RCA may include these techniques: Five whys, Failure mode and effects analysis (FMEA), Fault tree analysis, Ishikawa diagrams, and Pareto analysis.