In this paper we present an ant-based algorithm for solving unconstrained multi-level lot-sizing problems called ant system for multi-level lot-sizing algorithm (ASMLLS). We apply a hybrid approach where we use ant colony optimization in order to find a good lot-sizing sequence, i.e. a sequence of the different items in the product structure in which we apply a modified Wagner-Whitin algorithm ...

This paper corrects an improper expression in the economic order quantity (EOQ) model with two-warehouses and imperfect quality developed by Chung et al. [2009. A twowarehouse inventory model with imperfect quality production processes. Computers & Industrial Engineering 56, 193-197]. The modiT ed model yields a simple and corrected expression for the optimal order quantity and expected proT t ...

Waste accumulation in landfills, global warming and the need to preserve finite raw materials push governments industries shift towards a circular economy. Industrial symbiosis represents sustainable way of sharing resources converting unavoidable production residues into useful added-value products. In this context, we introduce new planning problem arisen between two units (PU) within an indu...

Coordinated replenishment problems are common in manufacturing and distribution when a family of items shares a common production line, supplier, or a mode of transportation. In these situations the coordination of shared, and often limited, resources across items is economically attractive. This paper describes a mixed-integer programming formulation and Lagrangian relaxation solution procedur...

Despite its great applicability in several industries, the combined cutting stock and lot-sizing problem has not been sufficiently studied because of its great complexity. This paper analyses the trade-off that arises when we solve the cutting stock problem by taking into account the production planning for various periods. An optimal solution for the combined problem probably contains non-opti...