Human Reliability Analysis (HRA) Methods

The following methods have been reported to EPRI as having been evaluated to determine whether they are NDMs or not. Available information on the basis for determining that a method is or is not an NDM and a summary of any completed NDM Peer Reviews are included as provided to EPRI by the party making the determination or conducting the NDM Peer Review.

Date	Title	Description	Implementing Document	Is this a “Newly Developed Method (NDM)”?	Link to NDM Decision Justification	Has a NDM Peer Review been conducted?	Link to NDM Peer Review Public Summary
June 2025	All Credible Dependency Combinations in Tree (ACDCT)	This new method allows JHEP development directly in the fault tree with no seed values required. With the potential to add and remove JHEPs from independent events in the tree in a similar fashion to how common cause is addressed.	CA-MISC-036	Y	CA-MISC-038	Y	CA-MISC-038
July 2026	EPRI Credible Dependent Failure Mechanisms (CDFM)	The CDFM method provides a risk-informed approach for HRA dependency analysis by identifying and explicitly modeling credible causes that could lead multiple Human Failure Events (HFEs) to fail in a dependent manner, rather than relying on post-processing combinations derived from PRA cutsets. HFEs are grouped based on shared functions, procedures, goals, support systems, or other credible dependency mechanisms, and these dependencies are incorporated directly into the PRA logic through Dependent Combination Events (DCEs), while a separate event accounts for residual dependencies from unknown causes.	EPRI 3002032023	Y	PWROG-26009-P	Y (findings being closed)	PWROG-26009-P