A dynamic storage location assignment model for a progressive bypass zone picking system with an S/R crane

Abstract

We propose a storage location assignment (SLA) model that considers workload balance and recirculation reduction under a storage space restriction. The SLA model balances the weighted sum of the number of picks and the number of visits across zones to reduce the recirculation. We then extend it to a storage location reassignment (SLR) model for limited relocation capacity. When the zone picking system runs short of relocation capacity for a SLA, the SLR model moves some pairs of products, which are prioritised to maximise the SLR. Simulations of industry orders show that the SLA and SLR models reduce the order picking completion time by 9.2%∼13.6% and 5.9%∼8.9%, respectively. The results imply that the SLR model is preferable when management needs to make minimal changes to SLRs.

Keywords:

• Zone picking system
• dynamic storage location assignment policy
• storage location reassignment policy
• binary-integer programming model
• simulation

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF-2020R1A2C2004320) and by the BK21 FOUR of the National Research Foundation of Korea (NRF) funded by the Ministry of Education (No. 5199990914451).