We consider the economic lot-sizing problem with perishable items (ELS-PI), where each item has a deterministic expiration date. Although all items in stock are equivalent regardless of procurement or expiration date, we allow for an allocation mechanism that defines an order in which the items...

In a recent paper, Liu [3] considers the lot-sizing problem with lower and upper bounds on the inventory levels. He proposes an O(n2) algorithm for the general problem, and an O(n) algorithm for the special case with non-speculative motives. We show that neither of the algorithms provides an...

We consider a generalisation of the lot-sizing problem that includes an emission capacity constraint. Besides the usual financial costs, there are emissions associated with production, keeping inventory and setting up the production process. Because the capacity constraint on the emissions can...

In a recent paper Gutièrrez et al. [1] show that the lot-sizing problem with inventory bounds can be solved in time. In this note we show that their algorithm does not lead to an optimal solution in general.