An event-driven simulation system is presented here for the transportation of liquid through pipeline network. An oil company produces various products in refineries and transport them mainly through pipelines to depots where the products are sold. A schedule is required for the transportation. The schedule defines the type of product to be transported, its amount, the start and end time of the transport, and the path. A schedule is called feasible if it takes into consideration tank capacity, product availability, deadlines, etc. Naturally, it is essential to check the feasibility of a schedule. Manual feasibility checking can be carried out only for a short time period, 3-4 days, and only if the complexity of pipeline network is modest. If schedules are needed for longer time periods, as long as 30 days, then a simulation model for the movements in the pipelines is needed. The implemented simulation system is applied by an Eastern-European oil company. The reduced stock levels and the better schedule means more efficient operation, less energy consumption, and less impact on the environment.