Modeling and solving the multi-period inventory routing problem with constant demand rates

The inventory routing problem (IRP) is one of the challenging optimization problems in supply chain logistics. It combines inventory control and vehicle routing optimization. The main purpose of the IRP is to determine optimal delivery times and quantities to be delivered to customers, as well as optimal vehicle routes to distribute these quantities. The IRP is an underlying logistical optimization problem for supply chains implementing vendor-managed inventory (VMI) policies, in which the supplier takes responsibility for the management of the customers' inventory. In this paper, we consider a multi-period inventory routing problem assuming constant demand rates (MP-CIRP). The proposed model is formulated as a linear mixed-integer program and solved with a Lagrangian relaxation method. The solution obtained by the Lagrangian relaxation method is then used to generate a close to optimal feasible solution of the MP-CIRP by solving a series of assignment problems. The numerical experiments carried out so far show that the proposed Lagrangian relaxation approach nds quite good solutions for the MP-CIRP and in reasonable computation times

Keputusan Pembangunan Pusat Distribusi yang Berkelanjutan dalam Rantai Pasokan

Rantai pasokan merupakan sebuah jaringan yang mengelola pengadaan bahan baku, transformasi bahan baku ke produk antara dan akhir, dan distribusi produk akhir ke pengecer atau pelanggan. Menentukan lokasi fasilitas (pusat) distribusi dalam rantai pasokan dengan kendala pemenuhan pasar memungkinkan Perusahaan lebih dekat kepada pelanggan, dan memberikan keuntungan kompetitif. Mengurangi waktu transportasi dan penggunaan minyak, biaya tenaga kerja dan peralatan merupakan faktor utama untuk membantu Perusahaan untuk mengurangi emisi karbon dan meningkatkan profitabilitas mereka. Dalam paper ini kami mengusulkan sebuah pendekatan MINLP untuk menyelesaikan model optimisasi untuk memutuskan pusat distribusi berbasis pertimbangan lingkungan

Decision support system for vendor managed inventory supply chain:a case study

Vendor-managed inventory (VMI) is a widely used collaborative inventory management policy in which manufacturers manages the inventory of retailers and takes responsibility for making decisions related to the timing and extent of inventory replenishment. VMI partnerships help organisations to reduce demand variability, inventory holding and distribution costs. This study provides empirical evidence that significant economic benefits can be achieved with the use of a genetic algorithm (GA)-based decision support system (DSS) in a VMI supply chain. A two-stage serial supply chain in which retailers and their supplier are operating VMI in an uncertain demand environment is studied. Performance was measured in terms of cost, profit, stockouts and service levels. The results generated from GA-based model were compared to traditional alternatives. The study found that the GA-based approach outperformed traditional methods and its use can be economically justified in small- and medium-sized enterprises (SMEs)

Road-based goods transportation : a survey of real-world logistics applications from 2000 to 2015

The vehicle routing problem has been widely studied from a technical point of view for more than 50 years. Many of its variants are rooted in practical settings. This paper provides a survey of the main real-life applications of road-based goods transportation over the past 15 years. It reviews papers in the areas of oil, gas and fuel transportation, retail, waste collection and management, mail and package delivery and food distribution. Some perspectives on future research and applications are discussed

Keputusan Pembangunan Pusat Distribusi yang Berkelanjutan dalam Rantai Pasokan

Rantai pasokan merupakan sebuah jaringan yang mengelola pengadaan bahan baku, transformasi bahan baku ke produk antara dan akhir, dan distribusi produk akhir ke pengecer atau pelanggan. Menentukan lokasi fasilitas (pusat) distribusi dalam rantai pasokan dengan kendala pemenuhan pasar memungkinkan perusahaan lebih dekat kepada pelanggan, dan memberikan keuntungan kompetitif. Mengurangi waktu transportasi dan penggunaan minyak, biaya tenaga kerja dan peralatan merupakan faktor utama untuk membantu perusahaan untuk mengurangi emisi karbon dan meningkatkan profitabilitas mereka. Dalam paper ini kami mengusulkan sebuah pendekatan MINLP untuk menyelesaikan model optimisasi untuk memutuskan pusat distribusi berbasis pertimbangan lingkungan. Kata kunci : rantai pasokan, pusat distribusi, keberlanjutan, MINLP, modelin

An Adaptive Large Neighborhood Search Heuristic for the Inventory Routing Problem with Time Windows

This research addresses an integrated distribution and inventory control problem which is faced by a large retail chain in the United States. In their current distribution network, a direct shipping policy is used to keep stores stocked with products. The shipping policy specifies that a dedicated trailer should be sent from the warehouse to a store when the trailer is full or after five business days, whichever comes first. Stores can only receive deliveries during a window of time (6 am to 6 pm). The retail chain is seeking more efficient alternatives to this policy, as measured by total transportation, inventory holding and lost sales costs. More specifically, the goal of this research is to determine the optimal timing and magnitudes of deliveries to stores across a planning horizon. While dedicated shipments to stores will be allowed under the optimal policy, options that combine deliveries for multiple stores into a single route should also be considered. This problem is modeled as an Inventory Routing Problem with time window constraints. Due to the complexity and size of this NP-hard combinatorial optimization problem, an adaptive large neighborhood search heuristic is developed to obtain solutions. Results are provided for a realistic set of test instances

An algorithm for the serial capacitated economic lot-sizing problem with non-speculative costs and stationary capacities

We address the serial capacitated economic lot-sizing problem under particular assumptions on the costs and the capacity pattern. We prove that when the involved costs are non-speculative with respect to the transfer to future periods and the capacity pattern is stationary for all levels, the optimal plan for each level can be obtained independently in O(T 3) time. This leads to an O(T 3L) algorithm for the problem with L levels. and the capacity pattern is stationary for all levels, the optimal plan for each level can be obtained independently in O(T 3) time. This leads to an O(T 3L) algorithm for the problem with L levels

Arbeitsbericht Nr. 2006-05, November 2006

Ilmenauer Beiträge zur Wirtschaftsinformatik Nr. 2006-05 / Technische Universität Ilmenau, Fakultät für Wirtschaftswissenschaften, Institut für Wirtschaftsinformatik, ISSN 1861-9223 ISBN 3-938940-06-