In this paper the appropriate combination of identification methods and input signal excitation is given in order to get a minimal measurement time in electrochemical impedance spectroscopy. It is shown that all the usual methods give the same estimation with the lowest error bound when a periodic signal is used as the input excitation. However, the measurement time depends on what signal is used. Several periodic inputs are described and compared. The measurement time is given for each signal. The minimum of the measurement time can be obtained by selecting the appropriate signal in each case. The paper gives the necessary tools to design the experiment using commercially available equipment or by programming multipurpose digital equipment. Finally, an example is given in order to illustrate the design procedure.