The purchasing division of private sector corporations have been under scrutiny over the lasts years due to the fact that it has been realized that large part of the profits of a corporation are due to well done purchases. This research will expose the study of purchasing activities in both private sector corporation and Government institutions. The basis for this paper were derived from the study of a productive institution of the Brazilian Federal Government whose activities are very similar to a private sector factory. The goal of this paper is to introduce alternatives to improve the inefficiencies of Government purchases. The objective is to bring the reality of Government purchases closer to private sector purchases methodology which would increase Government purchases agility and quality. The intent is to fulfill the demand of Brazilian Government, in all levels, Union, State and Municipalities, for a methodology to better manage their public purchases of goods and services, thus optimizing the initial chain of purchases, improving the relationship between Administration and suppliers.