Root cause analysis (RCA) is a problem-solving technique used to identify the main source of an issue. There are several synonyms for RCA, including causal analysis, source analysis, and problem diagnosis. These terms all refer to the same process of understanding the fundamental causes of a problem to prevent recurrence. Another synonym for RCA is fault tree analysis, which involves creating a visual representation of all the possible causes of a problem and determining the most likely root cause. RCA is an essential tool for quality management and continuous improvement in various industries, including healthcare, manufacturing, and engineering.