The purpose of this paper is to present the study developed jointly by TRANSPETRO/Natural Gas Department and Det Norske Veritas in association with Jardine Asset & Risk Management Solutions (Jardine) from the United Kingdom. The study was carried out with the objective of evaluating the security of supply of the overall TRANSPETRO Southeast gas supply network in 2005, 2006 and 2007, that provide gas in the Southeast region of Brazil to thermo plants, to vehicles and to industrial and residential consumers. The occurrence of contract shortfalls imply in heavy fines for the suppliers. To provide best in class analysis, state of the art software was used in order to count on powerful tools to model the gas supply system and to quantify the availability and the efficiency of the overall network and of the individual components.Copyright © 2006 by ASME