We propose a calculation method for transient analysis of linear time-invariant systems basing on the Mikusinski operator. Since signal-flow charts and scattering parameters (S-parameters) are used to describe the networks to analyze, the method is very vivid. The applied S-parameters form operators describing transmission and reflection of power waves from one node to an other of the network's signal-flow chart. Although the usage of operators exhibits some similarities to the Laplace transform, the effect of the operators is interpreted in time domain, and a signal transformation is not required. Thus, the presented calculation method is suitable to vividly analyze dynamic processes on electrical lines.