A Matheuristic for the Two-Echelon Inventory-Routing Problem

Effective coordination of operational decisions in today’s global supply chains has grown increasingly important. This paper considers a two-echelon inventory-routing problem under a vendor-managed inventory system, where suppliers are responsible for fulfilling the demands of geographically scattered customers through a set of intermediate facilities over a finite planning horizon. The problem involves determining the routing and delivery decisions to minimize the total routing and inventory costs. We introduce an effective two-phase matheuristic approach that combines tabu search and mathematical programming models. Computational experiments show that our approach achieves excellent results regarding solution quality and computational time. For small instances, the matheuristic finds 99 optimal solutions out of 165 known optimal solutions and achieves an average gap of (-2.32%)over 235 instances with a known best upper bound only, improving 159 known best upper bounds. Our approach also solves larger instances within a reasonable computational time and provides upper bounds for all 400 large-sized instances for the first time in the literature. Through a comprehensive series of experiments, we provide insights into the efficacy of different components of the proposed solution method

One-way or reusable distribution items? Department or Operations Planning and Control . •• Working Paper Series CIiE-v&Y CIt IlBDSABLE DIS1.1UBDTIQR lTIIIS? ONE-WAY OR REUSABLE DISTRIBUTION ITEMS?

ABSTRACT For companies it becomes still more important to pay attention to the load carriers, containers and package materials, that they buy, lease or rent to distribute their products due to increasing expenses for disposing the above distribution items (DIs) after use and a changing public opinion in favor of the environment. The same holds for the DIs used by their suppliers. A concrete framework, based on the life-cycles of DIs, is presented to provide in a systematic way insight into the potential pro's and con's of one-way and reusable DIs. Attention is paid to the strategic, functional, technical, environmental, logistics, information, organisational and financial aspects related to the use of DIs. Special attention is paid to the specific consequences of using the two types of DIs for suppliers and purchasers. Suggestions for further research are given

On the operational logistic aspects of reuse.

For still more companies, it is or will become important to pay attention to the possibilities for reusing the products they produce and the items, like pallets and package materials, that they use for distributing their products or which are used by others for supplying their products to them. One important reason for the above is the growing concern for the natural environment, among others resulting in environmental laws which not only force companies to take back their products from their customers and the items used for the distribution of these products when these products or distribution items (DIs) are no longer desired by these customers, but also to take care of the environmentally friendly disposal of these products and Dis. However, due to the same reason, this disposal is becoming still more difficult and expensive (see e.g., Cairncross, 1990). Apart from being forced by law, companies feel forced to do the above because of competition and public opinion. But there are more reasons why it may be worthwhile for companies to consider reuse: there are products, components, materials and DIs that can be obtained cheaper or more quickly via reuse than via purchasing or producing anew

Herstellen van productie-uitval

Het herstellen van productie-uitval kan worden omschreven als het transformeren van tijdens of direct na productie afgekeurde exemplaren of batches van producten in goede exemplaren of batches voordat deze naar afnemers worden gedistribueer