In this paper, we study novel variants of the well-known two-echelon vehicle routing problem in which a truck works on first echelon to transport parcels and fleet drones intermediate depots while second echelon, are used deliver from customers. The objective is minimize completion time instead transportation cost as classical problems. Depending context, drone can be launched at an depot once ...

We study when the operator f(Bw) is chaotic in the sense of Devaney on a Köthe echelon sequence space, where Bw is a weighted backward shift and f(z) = ∑∞ j=0 fjz j is a formal power series.

We consider in this paper a two echelon timber procurement system in which the first echelon consists of multiple harvesting blocks and the second echelon consists of multiple mills (e.g., sawmills), both distributed geographically. Demand is put forward by mills in the form of volumes of logs of specific length and species. Due to the impact of log handling and sorting on cut-to-length harvest...

We study the minimum concave cost flow problem over a two-dimensional grid network (CFG), where one dimension represents time periods and the other dimension represents echelons. The concave function over each arc is given by a value oracle. We give a characterization of the computational complexity of CFG based on the grid size (T periods and L echelons), the distribution of sources and sinks ...

The effective management of supply chains depends upon the ability of decision makers to control inventory while maintaining customer service at low cost. This paper examines an analytical model for the two-echelon one warehouse and multiple retailers system using (R, Q) inventory policies. A simulation model was developed to analyze the performance of the analytical model under conditions that...

Multi-echelon distribution systems are quite common in supply-chain and logistic management. They are used by public administrations in their transportation and traffic planning strategies as well as by companies to model their distribution systems. In the literature, most studies address issues related to the movement of flows throughout the system from the origins to their final destinations....

This paper focuses on the development of simulation-based environment for multi-echelon cyclic planning and optimisation in the product maturity phase. It is based on integration of analytical and simulation techniques. Analytical techniques are used to obtain initial planning decisions under conditions of stochastic demand and lead time, whereas simulation techniques extend these conditions to...

Multi-echelon distribution systems and more precisely, optimization of LTL routes related to them is one of the most popular subjects in the last 5 years of vehicle routing research. Although a plethora of models, methods and visions is found, it is still difficult to compare them because they use different terminologies and some authors insist on the fact there are a multitude of close but dif...

The Multi-Echelon Distribution Supply Chain (MEDSC) is a multifaceted structure, focusing on the integration of all factors that involved in the overall distribution process of finished products to the customers. The growing interest in multi-echelon distribution systems has highlighted the need to adopt an appropriate approach to ensure the efficient management of their complexity. While there...

Most research on supply chain management deals with settings where firms do not voluntarily get rid of inventory in the system. Since voluntary inventory reductions are often observed in practice, in this paper, we propose a (multi-echelon) model where the firm can dispose of excess stock through sales in the secondary market at each stage in the supply chain. What are called nested echelon bas...