This book is intended to serve as a reference book for research scholars who are pursuing their Master's & Doctoral Degree at various universities especially in the area of Composite Power Systems. Reliability analysis of a transmission system which uses FACTS components like TCSC and UPFC in combination with Series compensator is presented. Here the loss indices like Loss of Load Expectation, Loss of Energy Expectation will be evaluated. Reliability analysis is to be carried out by using two different techniques like State - Space technique and Series - Parallel representation. Implemented FACTS components into 6 bus RBTS which is categorized as composite power system. System Indices like Bulk Power Supply Disturbance (BPSD), Bulk Power Interruption Index (BPII), Bulk Power Energy Curtailment Index (BPECI), Probability of failure and Expected Energy Not Supplied (EENS) are being proposed to calculate at each and every bus to determine their respective performance. Above analysis will be carried out by incorporating different modules of FACTS elements in the transmission line. Comparison will be made out for the above analysis with different FACTS elements.