Storage allocation in a warehouse based on the forklifts fleet availability

Abstract

Product allocation is one of the most important duties in warehousing operations. Based on the time and the number of products to put away and retrieve, storage allocation can directly affect the efficiency of a warehouse in terms of both response and operation time. Traditionally, the product storage allocation is done based on the less distance of shipment but focusing on distance may decrease the efficiency of a warehouse in terms of efficient utilization of resources such as warehouse inbound shipping fleet. This paper proposes a storage space allocation model that considers the availability of forklift fleet in a warehouse instead of product shipping distance. The numerical example shows that storing the products based on the proposed model can reduce the volume of forklift fleet idle hours on days with fewer volume of receiving and shipping outs. The proposed model also reduces the overtime working hours on days with higher volume of receiving and shipping out products.

Sustainable Scheduling of Material Handling Activities in Labor-Intensive Warehouses: A Decision and Control Model

“…The results highlight the possibility to minimize the energy consumption, ensuring low cycle times. A further approach with the target of reducing the idle time of forklifts is proposed by Ghalehkhondabi and Masel [19]. The authors propose a storage space allocation model that considers the availability of forklifts.…”

“…In particular, (17) initializes the battery capacity in forklifts in the jobs allocated at the beginning of the planning horizon, whilst (18) calculates the residual battery capacity by first-order state transition between subsequent activities. Constraint (19) updates the residual battery capacity at the beginning of activity i, taking into account the eventual replacement with a fully charged battery. Constraint (20) guarantees that the capacity of the battery in any forklift is enough to complete job i, whilst (21) guarantees that the capacity of the battery in any forklift at the end of the final setup is not lower than the required final state.…”

“…Summing up, the second-step optimization problem (12)-(40) is a non-linear integer program, since cross-product terms z mn i β m i , s m i z mn i , r m i z mn i , and δ mt i z mn i are present in (19) and (33), (23), (24) and (25), and (34), respectively. The resolution of (12)-(40) allows the determination of the optimal job scheduling s m i , c m i , the battery replacement strategies z mn i , and the charging station energy scheduling ρ mt i .…”

“…Job index k [ 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30 ] Job priority p k [ 30,29,28,27,26,25,24,23,22,21,20,19,18,17,16,15,14,13,12,11,10,9,8,…”

A Method to Determine Allowable Speed for a Unit Load in a Pallet Flow Rack

“…Reducing the cost of warehouse operations is one of the main tasks in the designing of warehouses and the selection of material handling equipment and storage systems. Solutions of this task can be found by optimizing space utilization (e.g., Derhami et al, 2017), reducing the total travelled distance by the fork-lifts (Ghalehkhondabi and Masel, 2018), using automated storage and retrieval systems (AS/RSs), autonomous vehicle storage and retrieval systems (AVS/RSs) (Heragu et al, 2011) and Shuttle-Based Storage and Retrieval Systems (SBS/Rs) (Lerher et al, 2017) for increasing the throughput of warehouse operations.…”