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Vehicle Routing Problem with Private and Common Carriers
Zikmund, Adam ; Pelikán, Jan (advisor) ; Fábry, Jan (referee)
This diploma thesis deals with a problem from the field of combinatorial optimization called Vehicle Routing Problem with Private and Common Carriers (VRPPC). A complete undirected symmetric graph is given. The task is to satisfy demands in all nodes with minimal total costs. There are two possibilities of doing so. Either private fleet or common carrier can be used for the transport of the demanded goods. The private costs depend on the covered distance whereas the common costs are conditional only on the weight of demand. Several heuristic methods for solving this problem are proposed and tested on three experimental instances of different sizes (in terms of number of nodes). Emphasis is primarily put on comparison between the presented heuristic and the classical optimization approach, which can often lead to inferior results (especially in case of larger instances) because of the computational complexity of the given problem.
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Vehicle routing problem with heterogeneous fleet
Künzelová, Barbora ; Pelikán, Jan (advisor) ; Borovička, Adam (referee)
The master's thesis deals with the new modification of vehicle routing problem -- 3PL vehicle routing problem with heterogeneous fleet and split delivery. In addition to classical vehicle routing problem, we consider a heterogeneous suppliers fleet and also external carrier, which charges a fixed value per unit of transported goods. The reader is first introduces to vehicle routing problem, its history and possible solutions. Furthermore, the reader is acquainted with logistics and logistics providers. In the main part of this thesis is described 3PL vehicle routing problem and its mathematical model. At first we try to get optimal solution via CPLEX solver. But since this is an NP-hard task, heuristic method is proposed (in two variants) for solving this problem. The heuristic is then tested on the selected test tasks. Results obtained using the proposed heuristics are compared with the optimal solution. Even larger problems are then solved using this heuristics. In the end other modifications and possible improvements of this heuristic method are proposed.
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Support of management decision-making on transport networks
Přibyl, Vladimír ; Černý, Jan (advisor) ; Kavička, Antonín (referee) ; Peško, Štefan (referee)
The presented thesis is focused on a set of problems related to managerial decision-making concerning networks (particularly transportation networks), respectively - if we put it more precisely - the thesis focuses on the support of this decision-making by means of quantitative methods. A set of problems related to nets and decision-making concerning their individual parts or elements represents a very complex sphere which has been a subject of research for a number of decades. Out of this sphere, the thesis formulates and elaborates in great detail two problems, which - from the point of view of their practical significance - are important for the decision-making of managers of carriers, or the public sphere, and which have not been published in this form yet. The main point is the problem of how to find a subnet with a limited prolongation of routes between important pairs of vertices. Another problem is a design of a bus route in an area with a low demand. For each of these problems, the thesis offers an exact combinatorial solution method, furthermore a method based on integer linear programming, and - last but not least - also, of course, heuristic methods of solution. All these methods have been tested on a set of networks, which has been created for this purpose in a pseudo-random way in the frame of this thesis. The testing has been focused primarily on the comparison of the results provided by heuristic methods, which are of great importance - with regard to a great computational difficulty of exact methods - for feasible tasks on a larger scale. The tests have proved that the proposed heuristic methods are practically applicable and show results whicheven represent the optimal solution in a number of cases, or are only slightly distant from the optimal solution.
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Processing production in firm logistic
Altmanová, Lenka ; Fábry, Jan (advisor) ; Zouhar, Jan (referee)
The paper describes how logistic influence process in the firm, also there is a comparation with other firms in automobile section. And second part describes a case study of job scheduling in a mechanical-engineering production, the goal is to minimise the overall processing time. The production jobs are processed by machines. This problem is treated as a hybrid five-stage flow-shop. In other words, the job-processing job consists of maximum five tasks, it depends on product, because there is 12 products, each has own production flow. It is a new type of flow-shop in which the first-stage scheduling depends upon the time scheduling of the second stage, and so on. A mathematical model and a heuristic method is formulated, The problem is the NP hardness. The case study is solved with the heuristic method and the solution achieved represents a 10% reduction of the processing time for the given set of jobs.
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Route optimalisation for gas-meter reading
Šik, Petr ; Fábry, Jan (advisor) ; Pelikán, Jan (referee)
This thesis aims to find an optimal route taken by workers reading gas-meters. The text consists of three parts: the collection of necessary data, the selection and subsequent modification of the heuristic method and the calculation itself. Two techniques of data collection are applied: purchase from a specialised company and calculation based on geographical coordinates. These techniques are compared in the end. The method of the nearest neighbour is used for calculation, after being modified for this particular case. The calculation itself is done by the program named Gas-meters, which was created for the purpose of this thesis. The route potentially used by the gas company workers is then the result of the thesis. Furthermore, the thesis presents specific corporate savings possibly brought by using the presented program.
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