A method, system, and program product for identifying at least one bit failure among a plurality of semiconductor chips are provided. A first aspect of the invention provides a method of identifying at least one bit failure signature among a plurality of semiconductor chips, the method comprising: counting failures of each failing bit among the plurality of semiconductor chips; determining a most commonly failing bit (MCFB) among the failing bits; establishing a bit failure signature including the MCFB; counting failures of each failing bit on semiconductor chips on which the MCFB fails; determining a next most commonly failing bit (NMCFB) among the failing bits on semiconductor chips on which the MCFB fails; determining whether the NMCFB tends to fail when the MCFB fails; and in response to a determination that the NMCFB tends to fail when the MCFB fails, adding the NMCFB to the bit failure signature.