This paper considers calculation of structural reliability indices (SRI) for electrical power system (EPS), when «cutoff» failures are taken into account. It shows that existing software on typical EPS equivalent circuit data with minor additions aimed to account for specific EPS states. In fact, certain EPS elements (such as step down transformers, circuit breaker based automatic transfer switches, etc.) are considered as directional elements, in order to account for power flow direction. As a result, these elements have diverse SRI in upward and downward directions. The paper primarily assumes a parallel SRI calculation approach, which is based on two-stage EPS node «exclusion-restoration» process. Stochastic network reduction (SNR) technique is considered for certain stages of the calculation process. The paper shows that sequential SRI calculation technique has the largest impact on the resulting SRI. It proposes to use «-transformation» technique for SRI calculation of sequential elements. Decomposition-based SNR techniques are not recommended for SRI calculations of meshed EPS, because they can not ensure adequate result. In addition, the paper shows that direct connection between adjacent nodes at the «restoration» stage of the calculation process can be ignored for nodes of rank 2. Moreover, it proposes simultaneous failure matrix in order to account for simultaneous node failures caused by external power supply failures. The matrix forms at the «restoration» stage of the calculation process. It compensates fixed error of the «rhombus» network reduction technique.