Discrete Event Simulation in Improving The Service Level of Bulk Logistics

Abstract

Maritime bulk logistics systems depend heavily on port service performance, where vessel queuing and waiting times significantly affect operational costs and company service levels. High waiting times contribute to demurrage costs, supply delays, and reduced reliability in meeting production requirements. This study aims to analyze the vessel queuing system at a bulk port and evaluate the impact of operational improvement policies on service-level performance using a discrete-event simulation (DES) approach. A quantitative research design was employed, utilizing one year of historical operational data, including vessel arrivals, service times, and waiting times. Probability distribution fitting was conducted to define stochastic input parameters, and the simulation model was developed using ARENA software. The validated baseline model was subsequently used to test improvement scenarios, including extending port operating hours and increasing vessel carrying capacity The results show that extending operating hours from 12 to 24 hours increased service levels from 78.41% to 81.18% (an improvement of 2.77%) by reducing time-based waiting constraints. Meanwhile, increasing vessel capacity resulted in a higher service level of 84.52%, representing a 6.11% improvement over existing conditions. These findings indicate that capacity-based policies provide a more substantial impact on system performance than extensions of service time. This research implies that discrete-event simulation is an effective decision-support tool for evaluating operational strategies in maritime logistics. It also provides practical recommendations for improving service reliability and reducing demurrage risks in bulk port operations.