An Iterated Local Search for a Pharmaceutical Storage Location Assignment Problem with Product-cell Incompatibility and Isolation Constraints

In healthcare supply chain, centralised warehouses are used to store large amounts of products close to hospitals and pharmacies in order to avoid shortages and reduce storage costs. To reach these objectives, the warehouses need to have efficient order retrieval and dispatch procedures, as well as a storage allocation policy able to guarantee the safe keeping of items. Considering this scenario, we present a Storage Location Assignment Problem with Product-Cell Incompatibility and Isolation Constraints, that models the targets and restrictions of a storage policy in a pharmaceutical product warehouse. In this problem, we aim to minimise the total distance travelled by the order pickers to recover all products required in a set of orders. We propose an Iterated Local Search algorithm to solve the problem, and present numerical experiments based on simulated data. The results show a relevant improvement with respect to a greedy full turnover procedure commonly adopted in real life operations.