This study presents the extensions of a comprehensive project completed for Petrol Ofisi, the major petroleum products distributor in Turkey. In the completed project a decision support system was developed to minimise the total transportation costs of petroleum products under the static environment assumption. The aim of the current extensions, presented in this paper, is to organise the transportation activities, to be carried out throughout the planning year between the existing refineries and the coastal depots in a manner to meet the forecasted demand at the coastal depots, with minimum total inventory and transportation costs. An integrated freight transport planning model, incorporating inventory holding costs, is introduced under the dynamic environment assumption and comments are made on further extensions of the model.