DESIGN AND OPTIMIZATION OF PICKING IN THE CASE OF MULTI-ITEM MULTI-LOCATION MULTI-PALLET CUSTOMER ORDERS

Order picking related costs may account for up to 65% of the total expense of warehouse management. Hence, the implementation of robust design and optimization procedures for planning picking is addressed by researchers and practitioners.In this chapter the case of warehouses served by humans, in picker-to-parts systems, with a discrete picking organization is studied. Specifically, the case of orders including multiple different items, located in different aisles and requiring more than one forklift load to completely satisfy customer requests is analyzed, with the aim of minimizing the time for retrieving an order. Specifically, two aspects are studied:•the grouping of orders into a finite number of forklift missions, by assuring that each required item is picked in the required amount•the optimization of the routing to be followed by handling facilities in accordance with the objective of minimizing the total travelled distance and the computation of the number of handling facilities necessary for serving the warehouse aisles.