Chance constrained schedule design for heterogeneous fleet in liner shipping service


Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Industrial Engineering, Turkey

Approval Date: 2015

Student: AYSAN SHADMAND

Supervisor: SİNAN GÜREL

Abstract:

This study deals with designing a schedule for a heterogeneous fleet of liner shipping service by considering uncertainties. Shipping industry encounters with different kinds of uncertainties. Uncertainties of waiting times of the ships and handling times of the cargos might affect the actual departure times of the ships. In this study, service level is represented as the probability of on-time departure of a ship. Assuming that handling and waiting times are normally distributed, the problem is formulated as a mixed integer nonlinear stochastic program where the objective is to minimize the total fuel consumption. In formulation of the problem, three new aspects are considered. The first one is considering the heterogeneous fleet. The second one is considering the differences of the ports and the third is considering a new service level measure. The developed model is able to determine sailing times, departure times and service levels. Service levels are determined in a way to satisfy the overall service level of the service route. Overall service level could be defined by the shipping company for the entire route. The objective function of the model contains a nonlinear convex term. For handling the nonlinearity of the objective function, the model is reformulated by applying second order conic programming. The reformulated model could be solved by commercial software such as CPLEX. Finally, several experimental factors are defined and effects of these factors on fuel consumption cost and optimal solutions are analyzed. Moreover, for showing the benefits of the model, different comparisons are done.