Omya Hustadmarmor optimizes its Supply Chain

Study addresses a shipments-planning problem faced by Omya Hustadmarmor, a producer of large volume slurry products. From a single producing plant with limited production and tank storage capacity, multiple products are transported by different vessels to a number of tank farms that also have limited inventory capacity. The objective is to minimize the total distribution cost such that capacity constraints are not violated, i.e. neither stopping production at the plant, nor running out of stock at the tank farms. This Inventory-Routing Problem is solved by the use of a mixed integer-programming model and the application of a metaheuristic approach to obtain optimal solutions. At the company, the solution method was implemented successfully in a Decision Support System and resulted in a much more flexible and predictable supply chain.