Trailing for a better alternative - Logistic optimisation of dredging projects

Determining the way to make a reclamation project with many excavation areas or borrow areas, and several pieces of dredging equipment at minimum costs takes too much time to do by hand. A linear programming application is made to support the allocation of excavation areas and pieces of equipment to reclamation areas. Such an application was already available at HAM, but it could only be used in limited cases. The newly developed application can be used not just for allocation optimisation of soil in reclamation projects, but also for allocation optimisation in dredging projects aswell as a mix ofthe two as well. This application is a linear model of the cost items in a project. Preconditions areadded to the model for limits to available sand, limits to project duration, limits imposed byworking methods and options for working in joint ventures. The optimisation application can beused for obtaining the cheapest working method while making a tender, or while executing a project. The model is implemented in an executable and a reliable solver is included to calculate optimal solutions. A simple shell is made in Microsoft Excel that provides an interface familiar to the user. The program is tested for stability and speed. The program is also tested on a few projects to establish its practical value. By introducing an execution step 1 , the new optimisation program can be used for complete projects while planning preconditions can be included. Once a project has been cast in the model, it can be used for rapid calculation of different scenarios. In most cases, working methods obtained by optimisation proved to be cheaper than working methods obtained by traditional methods. Some additions can be made in the future. Options to generate input with Monte Carlo simulation can be included to the shell or in the executable. Time can be saved and mistakes can be avoided if the large amount of data is stored in a database system. A tool can be developed which represents the solution in some graphical form for easier interpretation and comparison. Chapter 2 deals with the problem and goal definition of this project. The optimisation model cannot be used in all types of projects. Chapter 3 describes in what cases and how to use the optimisation model. Chapter 4 Explains Why optimisation is chosen for achieving the objective of this thesis. The aspects of dredging processes that have an influence on the costs are described in section 5. Section 6 describes how a new model is made with the old model, tjur7^2 as a starting point. Section 7 explains Why it is advisable to resort to commercial software for solving the model. The experience obtained from three projects is described in section 8. Chapter 9 summarises the conclusions drawn from developing and testing the optimisation tool. The actions that have to be taken to finish the development and evolve the program "Optimise" into a tool with automated analysis, are written in section 10.Hydraulic EngineeringCivil Engineering and Geoscience