In this paper we introduce a new class of OR games: economic lot-sizing (ELS) games. There are a number of retailers that have a known demand for a fixed number of periods. To satisfy demand the retailers order products at the same manufacturer. By placing joint orders instead of individual orders, costs can be reduced and a cooperative game arises. In this paper we show that ELS games are bala...

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...

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 ...