In the two-echelon vehicle routing problem (2E-VRP), distribution network is split into two echelons. Different vehicles are operated on first and second echelon to maintain economies of scale adhere any restrictions that may be present in either echelon. Intermediate facilities located at borders echelons facilitate consolidation transshipment goods between Examples systems include express del...

Abstract Motivated by express and e-commerce companies’ distribution practices, we study a two-echelon electric vehicle routing problem. In this problem, fuel-powered vehicles are used to transport goods from depot intermediate facilities (satellites) in the first echelon, whereas vehicles, which have limited driving ranges need be recharged at recharging stations, transfer satellites customers...

This paper proposes a tabu search algorithm for the two-echelon vehicle routing problem with time windows and simultaneous pickup delivery (2E-VRPTWSPD), which is new variant of problem. 2E-VRPTWSPD involves three stages routing: (1) first-echelon vehicles start from depot to deliver cargoes satellites; (2) second-echelon satellites serve customers within in simultaneously manner finally return...

Freight transportation constitutes one of the main activities that influences economy and society, as it assures a vital link between suppliers and customers and is represents a major source of employment. Multi-echelon distribution is one of the most common strategies adopted by the transportation companies in an aim of cots reduction. Although vehicle routing problems are very common in opera...

Cointegrated VARMA models can be parameterized by using the echelon form, which is characterized by the Kronecker indices. Three diierent methods for estimating the Kronecker indices of cointegrated echelon form VARMA models are discussed and compared. They have the common feature of estimating the individual equations of the system separately and using order selection criteria. The small sampl...

Large multi-echelon inventory systems usually consist of hundreds of thousands of stock keep units (SKU). Calculating inventory policies for each product is a computational burden that necessitates the need for more efficient policy setting techniques that reduce computational time and increases managerial convenience. The main objective of our research is to investigate the effect of segmentat...

This paper explores the application of constrained clustering algorithms to inventory grouping based problems. Our research in this area is based upon a segmentation methodology that considers operationally relevant part attributes. In this paper, we present a brief review of literature on multi-echelon inventory models, and clustering applications to inventory segmentation. Finally, we discuss...

BACKGROUND After completion of axillary dissection, many breast cancer patients with axillary sentinel nodal involvement are found to have regional disease limited to the sentinel nodes. These patients are exposed to the morbidity of axillary clearance without any expected therapeutic benefit. METHODS Sentinel node biopsy was performed either with Patent blue dye or with a combined dye, radio...

We consider a two-echelon assembly system producing a single final product for which the demand is known. The first echelon consists of several parallel stages, whereas the second echelon consists of a single assembly stage. We assume that the yield at each stage is random and that demand needs to be satisfied in its entirety; thus, several production runs may be required. A production policy s...

We consider the classic continuous-review N stage serial inventory system with a homogeneous Poisson demand arrival process at the most downstream stage (Stage 1). Any shipment to each stage, regardless of its size, incurs a positive fixed setup cost and takes a positive constant lead time. The optimal policy for this system under the long-run average cost criterion is unknown. Finding a good w...