Some approximations in multi-item, multi-echelon inventory systems for recoverable items

Periodic Resource Reallocation in Multi-Echelon Repairable Item Inventory Systems

Given stock allocation in an inventory system, it is necessary to do reallocation periodically to address inventory imbalance and maximize availability. In this paper, we allow two opportunities to perform reallocation within a replenishment cycle. We derive a mathematical model to dynamically determine when to reallocate and how to reallocate. Experimental results show that multiplereallocatio...

Metric: A Multi-Echelon Technique for Recoverable Item Control

Neuroevolutionary Inventory Control in Multi-Echelon Systems

Stochastic inventory control in multi-echelon systems poses hard problems in optimisation under uncertainty. Stochastic programming can solve small instances optimally, and approximately solve large instances via scenario reduction techniques, but it cannot handle arbitrary nonlinear constraints or other nonstandard features. Simulation optimisation is an alternative approach that has recently ...

Coordination Policies for Multi-Echelon Multi- Product Inventory Systems

Starting in the 1960s, a number of academic works have focused in serial and distributed multi-echelon structures and in both deterministic and stochastic environments. Clark and Scarf (1960, 1962) developed a seminal work in which they presented optimal policies for a serial multi-echelon system. Schwartz (1973) studied a deterministic model having one warehouse and N retailers and showed that...

Modeling Multi-Echelon Multi-Supplier Repairable Inventory Systems with Backorders

This paper considers an inventory system responsible for repairable equipments located at several operational sites, each in different area. When a failure occurs at the operational site, spare parts are required. We analyze a multiple-supplier inventory system that includes an internal repair shop that offers several modes of repair with different repair times and an external supplier of spare...