MATHEMATICAL MODEL FOR SCHEDULING AND DETERMINING THE SPEED OF TRAMP PROBLEM BY CONSIDERING DYNAMIC DISPLACEMENT

• Main Author: Suryo Panotogomo A S, Muhammad
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/56961
• Institution: Institut Teknologi Bandung

PT. XYZ as a ship operator company serves general cargo tramp transportation services that can transport dry cargo without the need for special cargo partitions such in tramp oil or chemical tanker shipping services. PT. XYZ focuses on the onspot cargo market with the aim of getting a higher cargo delivery revenue than the Contract of Afreightment (COA) market. This causes the determination of the route and scheduling of ships in the PT. XYZ fleet will be more complicated to determine. Meanwhile the problem of operational methods, which is selecting the cargo to be served in the assigned ship still requires a long calculation process. Making the wrong cargo service decision can cause opportunity lost, so that it can affect the total profit of the tramp fleet. Furthermore, ship fuel component which a part of running ship costs can make up to 30.4 percent expenditure. In real conditions, the price of ship fuel that fluctuate can also affect the performance of the total profit of the shipping fleet, so that the fuel management on the tramp general cargo shipping fleet of PT. XYZ needs to be improved. Empirical study on ship bunker consumption that is commonly known in the shipping field states that fuel management can be achieved by adjusting the sailing speed of the ship and paying attention to the dynamic displacement conditions of the ship. Based on the problems above, this study will develop a mathematical model to optimize the total profit of PT. XYZ's fleet through the company's fleet scheduling using optimal speed determination and considering dynamic displacement. The research carried out pays attention to port aspects (time window, waiting time of loading/unloading service, ship-port compatibility, final port determination), ship aspects (ship capacity, ship service day, dynamic displacement), fuel costs, port costs, fixed costs, and the use of two types of fuel (Marine Fuel Oil and High-Speed Diesel). The results achieved in this study is a mathematical model of Mixed Interger Non-Linear Programming (MINLP) for tramp shipping services in the onspot market. The running analysis of the model developed with data input of PT. XYZ fleet and hypothetical cargo supply yield a solution that is always feasible. While the comparative analysis of scheduling using the developed model and operational methods of PT. XYZ with real cargo supply data input, shows that the developed model can increase the total profit by 30.6% compared to the previous profit. Sensitivity analysis of the main parameters in the range of -50% to +50% of the normal value, also shows the model output categorized as feasible.