# Root cause analysis > Root cause analysis (RCA) finds why a serious event happened, so fixes hit causes, not symptoms. It looks at the system, not at blame. Source: https://incidentkit.ai/glossary/root-cause-analysis ยท Updated Oct 5, 2026 Also known as: RCA, RCA2, comprehensive systematic analysis ## How an RCA works The team rebuilds the event from records and interviews. Then it asks how it happened (the active errors) and why (the hidden conditions in the system). AHRQ PSNet says it seeks system problems, not individual mistakes. A team from different roles does the work, with leaders involved. The VA patient safety center adds that the team keeps asking why, and focuses on how and why, not who. The weak spot is the fix. PSNet says RCAs often fail to produce lasting fixes because they lean on weak steps like training. RCA2 (root cause analysis and action) stresses stronger actions and measured results. ## Where it is expected - Joint Commission: every sentinel event needs a full analysis, most often an RCA. - CMS, nursing homes: look for deeper causes of system-wide problems (42 CFR 483.75(d)(2)(i)). - OSHA: find the root causes of an incident. There is often more than one. Example: a resident falls on the way to the bathroom after a sedative. The RCA finds sedative timing, uneven bed-alarm checks and unclear night-shift ownership. It assigns system fixes with owners and due dates. Mix-up: a root cause is not one cause or one person. A good RCA names several contributing factors and a fix for each. ## Frequently asked questions ### How long should a root cause analysis take? The Joint Commission expects the analysis and action plan within 45 business days of the event or of learning about it. A long gap loses detail. ### Is five whys enough for a serious event? Usually not alone. It follows one chain of cause. IHI notes a problem may have several root causes and points to RCA2 for more rigor. ### Who should be on the RCA team? People who know the process and front-line work, plus leaders, says the VA. Stay fair, and do not stop at the person closest to the event. ## Sources - [AHRQ PSNet: Root cause analysis (primer)](https://psnet.ahrq.gov/primer/root-cause-analysis) - [VHA National Center for Patient Safety: Root cause analysis (page and Guide to Performing a Root Cause Analysis, rev. 02/05/2021)](https://www.patientsafety.va.gov/professionals/onthejob/rca.asp) - [Joint Commission: Sentinel Event Policy (SE chapter), Comprehensive Accreditation Manual, Update 1, July 2026](https://www.jointcommission.org/-/media/tjc/documents/resources/patient-safety-topics/sentinel-event/camncc_20_se_all_current.pdf) - [42 CFR 483.75: Nursing home QAPI](https://www.ecfr.gov/current/title-42/section-483.75) - [OSHA: Recommended practices, hazard identification and assessment (incident investigation)](https://www.osha.gov/safety-management/hazard-identification) - [CMS: QAPI at a Glance, a step-by-step guide for nursing homes](https://www.cms.gov/Medicare/Provider-Enrollment-and-Certification/QAPI/downloads/QAPIAtaGlance.pdf) - [IHI: 5 Whys, finding the root cause](https://www.ihi.org/library/tools/5-whys-finding-root-cause) ## Related terms - [Five whys](https://incidentkit.ai/glossary/five-whys) - [Fishbone diagram](https://incidentkit.ai/glossary/fishbone-diagram) - [Corrective and preventive action](https://incidentkit.ai/glossary/corrective-and-preventive-action) - [Sentinel event](https://incidentkit.ai/glossary/sentinel-event) - [Just culture](https://incidentkit.ai/glossary/just-culture) - [Effectiveness review](https://incidentkit.ai/glossary/effectiveness-review) ## Related - [Root cause analysis and CAPA: methods and strong actions](https://incidentkit.ai/guides/root-cause-analysis-and-capa-guide) - [Root Cause Analysis: How to Run One That Leads to Action](https://incidentkit.ai/use-cases/root-cause-analysis) - [Root Cause Analysis Worksheet (5 Whys Template)](https://incidentkit.ai/templates/root-cause-analysis-worksheet) - [Five whys vs fishbone vs fault tree: how to choose](https://incidentkit.ai/blog/five-whys-vs-fishbone-vs-fault-tree) - [Incident investigations and root cause analysis](https://incidentkit.ai/product/investigations) - [Corrective and preventive actions (CAPA) tracking](https://incidentkit.ai/product/corrective-actions)