4,655 research outputs found

    LOGISTICS AND SUPPLY CHAIN STRATEGIES IN GRAIN EXPORTING

    Get PDF
    During the past decade, the grain shipping industry has become highly competitive and technologically advanced. These changes, along with the introduction of innovative shipping mechanisms, have made logistics management an important source of opportunity and risk for grain shippers. In this study, a stochastic simulation model was developed to evaluate the tradeoffs and effects of key variables on logistical performance in managing the grain supply chain. Average demurrage cost for the supply chain was $2.03 million with the greatest cost being for railcars and the least cost being for barges. Of the stochastic variables modeled, changes in export demand had the greatest impact on demurrage costs.Supply Chain, Grain Shipping, Logistics, Demurrage, Guaranteed Freight, Industrial Organization,

    Designing sustainable cold chains for long-range food distribution: Energy-effective corridors on the Silk Road Belt

    Get PDF
    Modern food production-distribution processes represent a critical stressor for the environment and for natural ecosystems. The rising flows of food across growing and consumption areas couple with the higher expectations of consumers for the quality of products and compel the intensive use of refrigerated rooms and transport means throughout the food supply chain. In order to aid the design of sustainable cold chains that incorporate such aspects, this paper proposes a mixed integer linear programming model to minimize the total energy consumption associated with the cold operations experienced by perishable products. This model is intended for food traders, logistics practitioners, retail managers, and importers collaboratively called to design and plan a cost and environmentally effective supply strategy, physical channels, and infrastructures for cold chains. The proposed model is validated with a case study inspired by the distribution of two example food products, namely fresh apples and ice cream, along the New Silk Road connecting Europe and China. The illustrated analysis investigates the effect of alternative routes and transport modes on the sustainability of the cold chain. It is found that the most energy-efficient route for ice cream is via rail over a northern route and, for apples, is via a southern maritime route, and, for these two routes, the ratios of the total energy consumed to the energy content of the food are 760 and 913, respectively. By incorporating the energy lost due to the food quality decay, the model identifies the optimal route to adopt in accordance with the shelf life and the conservation temperature of each product

    Design and Analysis of Efficient Freight Transportation Networks in a Collaborative Logistics Environment

    Get PDF
    The increase in total freight volumes, reducing volume per freight unit, and delivery deadlines have increased the burden on freight transportation systems of today. With the evolution of freight demand trends, there also needs to be an evolution in the freight distribution processes. Today\u27s freight transportation processes have a lot of inefficiencies that could be streamlined, thus preventing concerns like increased operational costs, road congestion, and environmental degradation. Collaborative logistics is one of the approaches where supply chain partners collaborate horizontally or/and vertically to create a centralized network that is more efficient and serves towards a common goal or objective. In this dissertation, we study intermodal transportation, and cross-docking, two major pillars of efficient, cheap, and faster freight transportation in a collaborative environment. We design an intermodal network from a centralized network perspective where all the participants intermodal operators, shippers, carriers, and customers strive towards a synchronized and cost-efficient freight network. Also, a cross-dock scheduling problem is presented for competitive shippers using a centralized cross-dock facility. The problem develops a fast heuristic and meta-heuristic approach to solve large-scale real-world problems and draws key insights from a cross-dock operator and inbound carrier\u27s perspectives

    Supply chain network optimization : low volume industrial chemical product

    Get PDF
    Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 60-62).The chemical industry is a highly competitive and low margin industry. Chemical transportation faces stringent safety regulations meaning that Cost-To-Serve (C2S), costs associated with products net flow from manufacturers to customers, consists of a big percentage of the delivered product cost. Supply chain practitioners in this industry need to make key logistics decisions to minimize C2S for profitability and business sustainability. In this thesis, we present a network optimization model to minimize the total C2S for SKU-1, a low volume and low margin industrial chemical with a customer base spread across North and South America. We use a mathematical linear program to investigate the effects on total C2S when available production capacities and sources are shifted. We develop the model as a minimum cost flow problem, and more specifically, as a production and transportation problem (PTP). We analyze the total C2S under three scenarios. In the baseline scenario there are three manufacturing facilities in the Midwest, South East, and Europe. In the second scenario, where the Midwest supplier is excluded from the network, the C2S increases by 3%. In the third scenario, where both the Midwest and South East facilities are excluded, the C2S increases by 13%. Under each scenario we calculate the C2S for each individual customer and identify the customers most impacted by the change in supply. Our results provide insight regarding the changes expected to the supply network under capacity constraints and how those changes may affect the profitability of individual customers.by Fred Dacha and Li Jin.M.Eng.in Logistic

    Distribution network redesign at Eastman Chemical

    Get PDF

    Optimal Global Supply Chain and Warehouse Planning under Uncertainty

    Get PDF
    A manufacturing company\u27s inbound supply chain consists of various processes such as procurement, consolidation, and warehousing. Each of these processes is the focus of a different chapter in this dissertation. The manufacturer depends on its suppliers to provide the raw materials and parts required to manufacture a finished product. These suppliers can be located locally or overseas with respect to the manufacturer\u27s geographic location. The ordering and transportation lead times are shorter if the supplier is located locally. Just In Time (JIT) or Just In Sequence (JIS) inventory management methods could be practiced by the manufacturer to procure the raw materials and parts from the local supplier and control the inventory levels in the warehouse. In contrast, the lead time for the orders placed with an overseas supplier is usually long because sea-freight is often used as a primary mode of transportation. Therefore, the orders for the raw materials and parts (henceforth, we collectively refer to raw material and part by part) procured from overseas suppliers are usually placed using forecasted order quantities. In Chapter 2, we study the procurement process to reduce the overall expected cost and determine the optimal order quantities as well as the mode of transportation for procurement under forecast and inventory uncertainty. We formulate a two-stage stochastic integer programming model and solve it using the progressive hedging algorithm, a scenario-based decomposition method. Generally, the orders are placed with overseas suppliers using weekly or monthly forecasted demands, and the ordered part is delivered using sea-containers since sea-freight is the primary mode of transportation. However, the end manufacturing warehouse is usually designed to hold around one to two days of parts. To replenish the inventory levels, the manufacturer considered in this research unloads the sea-container that contains the part that needs to be restocked entirely. This may cause over-utilization of the manufacturer\u27s warehouse if an entire week\u27s supply of part is consolidated into a single sea-container. This problem is further aggravated if the manufacturer procures hundreds of different parts from overseas suppliers and stores them in its warehouse. In Chapter 3, we study the time-series forecasting models that help predict the manufacturing company\u27s daily demand quantities for parts with different characteristics. The manufacturer can use these forecasted daily demand quantities to consolidate the sea-containers instead of the weekly forecasted demand. In most cases, there is some discrepancy between the predicted and actual demands for parts, due to which the manufacturer can either have excess inventory or shortages. While excess inventory leads to higher inventory holding costs and warehouse utilization, shortages can result in substantially undesirable consequences, such as the total shutdown of production lines. Therefore, to avoid shortages, the manufacturer maintains predetermined safety stock levels of parts with the suppliers to fulfill the demands arising from shortages. We formulate a chance-constraint optimization model and solve it using the sample approximation approach to determine the daily safety stock levels at the supplier warehouse under forecast error uncertainty. Once the orders are placed with the local and overseas suppliers, they are consolidated into trailers (for local suppliers) and sea-containers (for overseas suppliers). The consolidated trailers and sea-containers are then delivered to the manufacturing plant, where they are stored in the yard until they are called upon for unloading. A detention penalty is incurred on a daily basis for holding a trailer or sea-container. Consolidating orders from different suppliers helps maximize trailer and sea-container space utilization and reduce transportation costs. Therefore, every sea-container and trailer potentially holds a mixture of parts. When a manufacturer needs to replenish the stocks of a given part, the entire sea-container or trailer that contains the required part is unloaded. Thus, some parts that are not imminently needed for production are also unloaded and stored inside the manufacturing warehouse along with the required parts. In Chapter 4, we study a multi-objective optimization model to determine the sea-containers and trailers to be unloaded on a given day to replenish stock levels such that the detention penalties and the manufacturing warehouse utilization are minimized. Once a sea-container or trailer is selected to replenish the warehouse inventory levels, its contents (i.e., pallets of parts) must be unloaded by the forklift operator and then processed by workers to update the stock levels and break down the pallets if needed. Finally, the unloaded and processed part is stored in the warehouse bins or shelves. In Chapter 5, we study the problem of determining the optimal team formation such that the total expected time required to unload, process, and store all the parts contained in the sea-containers and trailers selected for unloading on a given day is minimized

    The cost of being landlocked : logistics costs and supply chain reliability

    Get PDF
    A large proportion of the least developed countries are landlocked and their access to world markets depends on the availability of a trade corridor and transit systems. Based on empirical evidence from World Bank projects and assessments in Africa, Central Asia, and elsewhere, this paper proposes a microeconomic quantitative description of logistics costs. The paper theoretically and empirically highlights that landlocked economies are primarily affected not only by a high cost of freight services but also by the high degree of unpredictability in transportation time. The main sources of costs are not only physical constraints but widespread rent activities and severe flaws in the implementation of the transit systems, which prevent the emergence of reliable logistics services. The business and donor community should push toward implementation of comprehensive facilitation strategies, primarily at the national level, and the design of robust and resilient transport and transit regimes. A better understanding of the political economy of transit and a review of the implementation successes and failures in this area are needed.Transport Economics Policy&Planning,Transport and Trade Logistics,Common Carriers Industry,Economic Theory&Research,Rural Roads&Transport

    Logistics real estate markets: indicators of structural change, linking land use and freight transport

    Get PDF
    The system of physical distribution that comprises transport and logistics, warehousing and wholesale, is an ideal indicator of structural change. Distribution and logistics have developed dynamically, with respect to new technologies, corporate restructuring, and a changing market environment. Whereas traditional logistics were characterized primarily by the demand of manufacturing customers for the shipment of bulk-commodities, modern production and service systems require frequent deliveries over great distances, with high inventory turnovers instead of storage. As a consequence, the locational profiles of distribution firms have changed as well, both at a large-scale level and within metropolitan regions. Based on recent findings of the European Warehousing Index, the paper points out how the European system of goods movement has changed in terms of regional distribution markets and warehousing location. Secondly, the consequences of locational dynamics within metropolitan regions are considered. The dominance of the truck and the suburbanisation of large distribution centres raise serious concern about logistics management, traffic reduction and locational policy. Referring to selected places such as the Ruhr Area, Hamburg or Berlin-Brandenburg, the paper demonstrates how critical the relationship between cities and goods distribution is becoming, with regard both to the regional economy and the urban environment. Is there a chance for regional, spatially oriented management of supply chains? In the case of the Ruhr Area, it is also questioned whether a certain 'knowledge milieu' (logistics research, applied sciences) may contribute to this goal. The particular benefits of investigating logistics real estate markets are fourfold: - They allow for a precise insight into regionally differentiated developments. - They connect the system of 'flows' with material 'space'. - They demonstrate that structural change is by no means neutral for the environment, regarding specific transport and land use implications of distribution. - They represent the emergence of new players in land use planning and policy (i.e. developers), thus shaping the system of political regulation.

    Facility location decisions with environmental considerations. A case study from the petrochemical industry

    Get PDF
    The recently growing concerns of customers and governments about environmental protection and greenhouse gas reduction have forced companies to integrate the topic of environmental sustainability into their decision making. Facility location decisions are of special relevance in this respect because of their strategic nature. Furthermore, many different trade-offs must be considered, for example between operational costs and customer service. But as soon as environmental issues are concerned, other critical issues must be considered as well. Based on a case study from the petrochemical industry, this paper extends two basic facility location models and shows the impact of distribution network-design decisions on the economic and environmental performance of the company. The results show a trade-off between total (distribution) costs and transport carbon emissions. (authors' abstract
    • …
    corecore