The role of Advanced Algorithm in Hong Kong Sea Port

The role of Advanced Algorithm in Hong Kong Sea Port

Introduction

An algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Starting from an initial state and initial input, the instructions describe a computation that, when executed, proceeds through a finite  number of well-defined successive states, eventually producing "output" and terminating at a final ending state. The transition from one state to the next is not necessarily deterministic; some algorithms, known as randomized algorithms, incorporate random input.

Application

The Port of Hong Kong, located by the South China Sea, is a deep water seaport dominated by trade in containerised manufactured products, and to a lesser extent raw materials and passengers. A key factor in the economic development of Hong Kong, the natural shelter and deep waters of Harbour provide ideal conditions for berthing and the handling of all types of vessels.

The strategy of outsourcing yard trucks is a decision making problem that container terminals are currently facing. Yard truck scheduling and storage allocation are two major operations that related to yard trucks management Problem. In this case, the studied yard trucks management problem is focused on integration of the yard truck scheduling and the storage allocation problems. The objective is to minimize the total operation cost of in-house trucks, out-sourced trucks, and delay of requests. An approach with genetic algorithm and linear programming is proposed to solve the problem. The effectiveness of the proposed method is analyzed from using practical data obtained from Hong Kong terminals.

With the development of container throughput, Hong Kong container terminal companies are dealing with more and more containers which are needed to be transported on time and at low cost. Since the daily throughput of containers in Hong Kong fluctuates significantly and yard truck is quite an expensive equipment, it is economical not viable to keep a full team of fleet

to cover the entire service., the decision of how many trucks should be maintained in-house and how many should be out-sourced become a problem that will influence the operations expenses of the terminal. However, the strategy of determining the number of the two different kinds of trucks used in container terminal is related to the operations in container terminals. In general, operations in container terminals include berth allocation, quay crane scheduling, yard truck scheduling, yard crane scheduling and storage allocation

Solution:

To deal with the real-world problem of determining the strategy of managing yard trucks to minimize the cost, a two steps method is proposed. The first step is to calculate the amount of trucks that should be used in every single day. A genetic algorithm (GA) is proposed to solve it, and the second step is to calculate the number of bought trucks and rent trucks. This step is formulated as a Mixed Integer Programming (MIP) model and Ilog Cplex is used for solution.

Algorithm for the Number of Trucks Determination:

An iteration method is applied for calculation of the number of trucks to cover all the jobs with minimum delay. Assuming the number of trucks is fixed at first, and use the genetic algorithm to calculate the delay of jobs. Then, add one more truck and calculate the delay again. If the delay becomes shorter, continue to add one more truck and do the re-calculation until no changes on the delay, otherwise, minus one truck, and calculate the delay until the delay become longer.