A Solution Proposal to Vehicle Routing Problem with Integer Linear Programming: A Distributor Company Sample

It was aimed to minimize the total distance of the routes under the capacity constraint of the routes that a distributor company has drawn in the direction of the demands. To this end, a route to Gebze-based steel production and distribution was drawn up to meet all the demands of a fabrication plant. In order to determine the minimum total distance routes, the solution recommendation by adapting the Capacity Constrained Vehicle Routing Problem (CVRP) which is one of the basic route problems using Branch and Cut algorithm of 0-1 Integer Linear Programming (ILP) was introduced. Distances between the nodes that make up the route are measured via Google Maps. Optimal solutions were obtained by using LINDO computer software to solve the problem.

Livro de atas do XVI Congresso da Associação Portuguesa de Investigação Operacional

Fundação para a Ciência e Tecnologia - FC

Electricity and Fuel Consumption in a Lean Energy Supply Chain

Human activities are the main sources of environmental pollution. Awareness about this fact, motivated us to make changes in different paradigms of our lives including industrial or personal activities. Environmental activities assumed to have conflict with financial objectives, in this study we try to align business requirements with environmental concerns. Among all human activities, generating energy has the most negative impact on the environment. The major part of the generated energy will be consumed in transportation and industrial demand which makes them the most effective targets for the reduction of greenhouse gas emission. In a lean environment, small batch sizes increase the number of set-ups and consequently, energy consumption in manufacturing. On the other hand, small batch sizes increase the delivery rates and complexity of transportation. Therefore, the focus of this study will be on reducing the environmental impact of human activities in transportation and industrial loads as a part of lean supply chain. The focus in transportation will be on trucking with gasoline or diesel as the source of energy. In industrial loads, the emerging opportunities after deregulation of the electricity market and incentive programs toward cleaner productions encouraged us to focus on electrical demand in the industry. Despite motivations for reducing emissions in supply chain management, lack of knowledge and expertise in measuring, modeling and optimizing energy consumption is a barrier in production section. In this dissertation, a framework of a power measurement and simulation will be introduced. In the next section, a production planning model incorporating energy will be developed considering different states of electricity consumption (idle, startup, etc.). As the next segment of the supply chain, a method for optimal carrier selection and routing will be developed and tested based on real world data. This model can use the advantage of geographically distributed carriers while utilizing private fleet at an acceptable level. Based on the insight developed in transportation and industrial loads, an experience based performance measure will be developed to quantify the performance and associated energy consumption in the supply chain

Modeling Industrial Lot Sizing Problems: A Review

In this paper we give an overview of recent developments in the field of modeling single-level dynamic lot sizing problems. The focus of this paper is on the modeling various industrial extensions and not on the solution approaches. The timeliness of such a review stems from the growing industry need to solve more realistic and comprehensive production planning problems. First, several different basic lot sizing problems are defined. Many extensions of these problems have been proposed and the research basically expands in two opposite directions. The first line of research focuses on modeling the operational aspects in more detail. The discussion is organized around five aspects: the set ups, the characteristics of the production process, the inventory, demand side and rolling horizon. The second direction is towards more tactical and strategic models in which the lot sizing problem is a core substructure, such as integrated production-distribution planning or supplier selection. Recent advances in both directions are discussed. Finally, we give some concluding remarks and point out interesting areas for future research