Abstract: A method of fault criticality assessment using neural twins includes converting a netlist into a neural twin by replacing each circuit element of the netlist with a neural-network-readable cell equivalent; and replacing each wire with a neural connection. Bias value adders are inserted at locations in the neural twin; and these bias value adders are used to apply a bias that represents a perturbation in the signal propagated by that connection. For each perturbed bias at a corresponding site selected to be perturbed, a loss value is calculated for the neural twin; and the site is classified, using a neural-twin-trained classifier, as critical or benign based on that loss value.