(372a) Nonlinear Optimal Control Approach to Scheduling Problems

Planning and scheduling are activities of major economic importance. Among various planning and scheduling problems, this paper focuses on the scheduling of crude oil and petroleum derivatives in ports: the jetty scheduling problem. The problem has combinatorial (allocation, sorting) and nonlinear (product blending) aspects, and multi-objective goals (minimization of different costs). We consider problems composed by tankers, tanks, pipelines, and jetties. Simulation models have been used as basis for this formulation. Moreover, real-life instances of the problem are of large scale and, if one wants to solve them in the daily operation of a harbor, they must be solved within minutes in common computer stations. This article proposes an original approach based on a continuous nonlinear optimal control model, without integer (binary) decision variables, which can reduce the problem's size. Numerical experiments are presented using efficient NLP methods, such as LSGRG2, MINOS, and SNOPT