An Optimization Study For The Tramp Shipping System

The growth in world trade has continued to outstrip growth in most countries' Gross National Product throughout the closing years of the 20^th century and looks set to continue for the foreseeable future. The ocean shipping industry has become the undisputed monopoly on transportation of large volumes between continents. There is no doubt that the tramp shipping as a member of the ocean shipping family its status is unshakable.With continuously increasing levels of the supply chain globalization management and rapidly rising the concept of customized service, the tramp shipping industry has to face the serious challenge if its management is still limited to traditional tools and methods even it has a long history, and if the operators make some positive change in this time the serious challenge maybe can turn into its rare opportunity.In the new situation and conditions of competition, the tramp shipping enterprises how to get the goal, one can achieve huge profits return, the other can meet the specific needs of customers in the greatest extent possible in the same time, is a worthy research field. The higher application and theoretical value is clear. Therefore, the dissertation chose the tramp shipping system to do some in-depth studies from a maritime supply chain management research perspective.First of all, the paper holds these perspectives that the continued development of the world economy and the sustained prosperity of the international shipping market laid a solid foundation for the tramp shipping' further development Increasing levels of the supply chain globalization management, increasingly fierce competition trends and the operation of the tramp shipping in the world occasional practice objectively look forward to the shipping firms to continuously enhance the management decision-making level, etc, all is the intrinsic driving force to study the system based on an operations research perspective. Shipping EDI usage, relevant disciplines rapidly development and some new types of simple optimization software provide the support platform on data and tools for this study. Thus in this context and conditions the paper chose to do some optimization research on tramp shipping system with a maritime supply chain management perspective is feasible and meaningful.Based on the analysis and summing-up of a great number of relative existing literatures and researches, the paper hold this view that almost of these research were related to a single type of cargo, specific volume, fixed loading and unloading ports, fixed freight, fixed time windows, minimize the number of ships and transportation costs as a target and almost of them are one-time stage static decision-making problem. It is truly rare that the researchers study the inventory routing based on maritime supply chain. Few relevant researchers explore this problem with a static single cycle strategy, the goal function is minimizing the number of ships and the transportation costs rarely involve multi-stage inventory balance. The Research and Development of decision support system based on optimization for tramp shipping covering from route optimize, ship management, security management, cost control, performance assessment, commercial ship fleet operation mode and fleet deployment, is the focus of future research and hot.On the planning ship vessel based on Pareto Route, the paper gives the definition of Pareto Route at first considering the time factor as a main breakthrough, the paper definite the time that one ship must arrival one port in contracts as the limit number, then expand the navigation necessary time between two ports from a traditional real number to an interval number, under these conditions, the paper abstracted the ship routing based on operational levels to a problem that how to search a Pareto Route in a generalized graph with generalized weights. The paper built two nonlinear programming models: one is the Mixed Integer Nonlinear Programming Model based on the Pareto Route's characteristic function, the other is Adjusted Mixed Integer Nonlinear Programming Model, we labeled as MINLP and MINLP-â…¡respectively. We proved that the relations between the optimization solution of two models and the Pareto Route are the equivalence relations, and the relations between two models are the equivalence relations, too. Simulation calculations in this study clearly showed that the models are reasonable and effective.On the study of the ship deployment and assignment scheduling based on Pareto Route, the paper constructed a Mixed Interval Integer Programming model, which based on considering a single loading port and meeting the customer's special requirements for the shipment, labeled as MIIP, at first. Then do the comparative studies between the MIIP model and the Rouen model. Simulation calculations in this study clearly showed that there are three improvements compared to Ronen model in new MIIP model, one is the numbers of binary variable significantly reduced in MIIP model, second, the MIIP is more robust than the Rouen model and correct the Rouen model's errors, the last one is that the first time considering the customer special requirements in MIIP model, and it is also true to expand Seong Cheol model.Then a series of optimization models was established considering multi loading ports and many types of cargo and multi loading ports, labeled as MIIP-â…¡model and MIIP-â…¢model respectively. We prove that three optimization models are all convex programming. Usage the duality techniques we proved the three basic theorem, which proved the existence of optimal solutions, between the primal model and the dual model. We gave a heuristic algorithm for the sub problem of loading cargo and the mixed two-stages heuristic algorithm strategy for the optimal models in this chapter. Simulation calculations clearly showed that the models are effective.On the study of the inventory routing integrated optimization based on maritime supply chain management, the paper claimed that the essence of this problem is a technical management issues and how to determine the optimization shipment in a tramp shipping system under some gave restrictive conditions such as the ship transport capacity, the storage capacity of the ports, the ability of suppliers and manufacturers of production capacity, the objective function is minimized the operation of the total system cost, planning for the future of a number of cycle transport arrangements. In maritime supply chain management, the optimal shipment is required to meet the prerequisite of a loading and unloading port stocks balanced, and it is no more than the ship transport capacity and the port warehousing capacity constraints. The optimal shipment is need to meet the demand of production and also decided the port warehouse inventory levels.The paper constructed a multi-period multi-type cargo involving many types of cargo ships deployment inventory routing optimization models Integrated Optimization of Inventory Routing based on operations level at first, labeled as IOIR model. Then gave a two phases combined optimization heuristic algorithm strategy. The first phase is fellow not consider shipping schedules restrictions, it is say to solve RIOIR at first it can get the inventory strategy at each port and the shipment to each port, the second phase is to decide which ship is the best arrangements from a candidate schedule with a heuristic algorithm named a saturated vertex in task set in a generalized bipartite graph with weights which is the transportation cost. We gave three basic theorems and analysis of the relationship between the RIOIR model and the IOIR model, Simulation calculations clearly showed that the models are effective and the algorithms are reliability.Simulation calculations concluded that the IOIR model's restrictions are compatible, the optimize shipment can make the loading and unloading cargo stocks to multi-stage dynamic balance, the IOIR model has a sensitive response when input different initial number, it show that the IOIR model can truly dynamic simulate the real operation with multi-port, multi-cargo, multi-ship in a maritime transportation system, The model may be used for business scene analysis. In meeting the shipment does not exceed the ship capacity conditions the simulating results are stability global optimal solutions means the IOIR model has good robustness.In the study of decision support system based on optimization for tramp shipping, a three-dimensional irregular framework concept was built in the paper, it cover ship optimize real-time deployment, operation and performance assessment and forecast decision-making in a middle and long-term based on econometric time series analysis. The paper explored the three major sub-systems' working methods and working flow. A major study on the operation of the database subsystem and the database subsystem based on historical statistical time-series database workflow and working methods, The model subsystem focuses on the analysis of subsystems based on the macroeconomic time series models and the number of models based on operational, conversation management subsystem is introduced the main design features and strategies, at last the paper brief introduced final choice of development tools, the existing research base and potential problems for the development.In addition, although the paper is based on maritime transportation, but all these optimization models can expand to the general logistics system similar to the issues, since the current logistics systems for the general study of the distribution usually focus on the carriers to the smallest number and the lowest transportation costs without considering the optimize carriers' deployment. Therefore, in this sense the series of optimization models were constructed in this paper have higher theoretical value.In summary, the dissertation not only stresses the methods for detailed analyzing and describing these problems with precision mathematical language but also discusses the theoretical skill and design effective algorithms for solving them.