A multiproduct Pipeline provides an economic way to transport large Volumes of refined petroleum products over long distances. In such a pipeline, different products are pumped back-to-back without any separation device between them. Sometimes, multiproduct pipelines can be connected together, resulting in a more complex system commonly named multi-pipeline system. This paper proposes a new discrete mathematical approach to solve short-term operational planning Of multi-pipeline systems for refined products. This model is based on a discrete approach that divides both the planning horizon into time intervals of equal duration and the individual polyducts into packages of equal volume each containing a single product. Numerical examples are solved in order to show the performance of the proposed model. All the instances are implemented with the OPL modeling language running CPLEX as solver. (C) 2009 Elsevier Ltd. All rights reserved.