T The operating circuit is the telephone line/channel used by the customer. The operating circuit is determined by the value of outgoing traffic and the percentage of blocking probability. The value is 1%. The need for implementing the operating circuit is determined by the percentage occupancy value.This final project analyzes the effectiveness of implementing the number of operating circuits at the Jatinegara 2B automatic telephone exchange on five destination central trunk group segments, namely the GB2D central, KTIB central, SLPC central, TB1C central, KLDB central. The implementation of the number of operating circuits can be determined from the location of the area around the central or the behavior of telephone users, depending on which one will be considered first in planning the implementation of the number of circuits.The value of the percentage occupancy can determine the effectiveness of implementing the number of operating circuits. The occupancy value that can be said to be effective is between 60% - 80%. From the results of the research on circuits operating using the Erlang table and occupancy calculations, the highest occupancy value was obtained in the JT2B - TB1C section, which was 61.81% with 22 circuits. And the lowest occupancy value occurred in the JT2B-KT1B section, which was 31% with 10 circuits.