When configuring RFID tag identification (ID) processes using the FSA protocol without the muting option, it is fundamentally necessary to determine the optimal values for frame size and the process termination time (TT) so that an RFID reader can identify all tags in its interrogation zone with a preassigned level of confidence and minimum delay. In this Letter, we show that for given tag population N and confidence level (CL) α, the optimal frame size is N/ ln 2 in the context of minimising the ID delay for given CL, and the TT increases logarithmically with N and 1/(1 − α); more specifically, the TT is simply given by ⌈log2 N − log2 (1 − α)⌉ when the optimal frame size is used. Through computer simulations, we verify the effectiveness of the proposed formulas in optimally configuring ID processes.