A Root Cause Analysis is a relatively loosely used term in industry, but here at LBNL, we only call an analysis a Root Cause Analysis if it meets a certain level of rigor, primarily based on the method by which it is accomplished.
Root causes are the underlying or basic cause of an issue that can reasonably be identified and management has the control to fix, and when fixed, will preclude recurrence or significantly reduce the likelihood of recurrence of the same or similar issue. Root causes are typically discovered through deeper analysis and are one level beyond apparent causes.
The key distinction between RCA and ACA is that an ACA does not require the use of formal analytical methodologies—such as barrier analysis, change analysis, or error precursor analysis—as outlined in LBNL’s Issues Management Manual (PUB-5519). These formal methodologies are consistent with those used in Department of Energy (DOE) causal investigations. An ACA is a more basic analytical approach used to identify the evident or likely reasons behind an incident or finding.
Because ACAs are less methodologically rigorous, they require fewer resources and less time for analysis and fact-finding compared to RCAs. Just like many programs at the Lab, LBNL applies a risk-graded approach and only requires RCAs for high-risk issues and ACAs for medium-risk issues. There are a few other process requirements for the RCA process, which are defined in detail in PUB-5519.
