Caspian Journal of Applied Sciences Research 4(3), pp. 8-18, 2015 Journal Homepage: www.cjasr.com ISSN: 2251-9114 Multi-product pipeline scheduling using simulation optimization Ramin Geramianfar 1,* , Mohammad Reza Pakzad 2 , Reza Tavakkoli-Moghaddam 3 1 Department of Automated Production Engineering. École de technologie supérieure (ETS) Montreal, Canada. 2 Department of Industrial Engineering, South-Tehran Branch, Islamic Azad University, Tehran, Iran. 3 School of Industrial Engineering, College of Engineering, University of Tehran, Tehran, Iran Multiproduct pipelines permit to transport huge amounts of refined oil products from supply origins to distribution centers. Batches of refined products are injected one after the other in the same pipeline, without any separation device between them. The objective is to obtain a sequence of batches of different products to be sent to satisfy the demand without violating any constraint. In this paper, a decision tool using simulation optimization for scheduling of a multi-product pipeline system, which connects a refinery to several distribution centers, is performed. The simulation model is applied to assess each scheduling and then simulation optimization is used to find a set of optimum or near- optimum of decision variables. In comparison with the presented mathematical model by Cafaro and Creda (2008), the defined tool in this paper causes an efficient improvement in reducing total costs. The provided methodology is able to find a satisfactory scheduling in long time horizons. As a result the simulation-optimization model is an appropriate and efficient for solving the real-world problems. © 2015 Caspian Journal of Applied Sciences Research. All rights reserved. Keywords: pipeline; scheduling; simulation; optimization 1. Introduction One of the oil supply chains is the oil transportation from the refinery to the distribution centers. Oil transition from refinery to the distribution centers can be performed by different ways such as railway, trailers, ships and pipelines. Among these ways, the pipeline is the cheapest and safest one for delivering a huge amount of the oil products from the refinery to the distribution centers. In comparison with other transportation ways, the pipeline method can be performed in bad weather conditions continuously and almost without any interruption. Moreover, by not causing air pollutions and congestion on highways and rivers, the pipelines are considered as a very * Corresponding address: 1100, Notre Dame Street Ouest, Montreal, Quebec, Canada H3C 1K3. E-mail address: ramin.geramianfar.1@ens.etsmtl.ca (Ramin Geramianfar) © 2015 Caspian Journal of Applied Sciences Research; www.cjasr.com. All rights reserved. important matter in safety and environmental issues. Some products such as gasoline, kerosene, jet fuel, diesel and liquid gases like propane and butane can be transported by pipelines. Generally, pipelines have some receipt and delivery points on their way. Liquid products are pumped by centrifugal pumps that are based on pumping stations (one is at the origin and the rest ones are along the pipeline). The booster pumps are located along the pipeline for adjusting pressure and oil flow. Batches of different oil products are pumped into the pipeline one after the other, without any separator tool among the batches. Mechanical separators that called pigs are used in the multi-product pipelines rarely. If two