In an extension to a previous article, this article shares findings from a simulation study that specifically compared cycling strategies for manually operated forklifts in the shipping warehouse of a plywood factory. The simulation study compared two alternate operational strategies:

1. Separated a) putaway and b) retrieval forklift pools
2. Single joint forklift pool for combined putawa-retrieval operation

The joint forklift pool strategy is based on the idea of all forklifts operating in combined cycles. First, a plywood stack is put away in the warehouse. Then, before heading back to the manufacturing area, the forklift retrieves a plywood stack from the warehouse and loads it into an outbound shipping truck. As demonstrated in below video, this results in combined cycles.

In comparison, separate dedicated forklift pools implement a clear cut between putaway and retrieval operations. One pool of forklifts is responsible for putting away plywood stacks from manufacturing in the warehouse. And another pool of forklifts is responsible for retrieving shipments from the warehouse.

Joint forklift pool with double cycling of forklifts reduced forklift utilization during peak hours

The simulation study concluded the following:

1. Joint forklift pool reduces need for forklifts during peak hours, i.e. total demand for forklifts and forklift drivers
2. Without any additional operational strategies or constraints in place, a joint forklift pool with double cycling of forklifts causes the risk of increasing max. truck loading time
3. Average truck loading time was not impacted by operational strategy, i.e. similar for both a) joint and b) separated forklift pool

The simulation study was conducted with a customized SimPy model, based on the warehouse zoning simulation template purchaseable in the SCDA shop

The simulation study was conducted in Python, using a SimPy based template with additional project-specific customizations. The template, used for customization in this study, was the simple SCDA warehouse zoning SimPy model.

• Link: Warehouse zoning SimPy model

You can find additional information on above simulation template and other simulation studies conducted with the model for the same plywood warehouse in below article.

• Link: Efficient and simulation-based warehouse zoning

Linnart Felkl

Data scientist focusing on simulation, optimization and modeling in R, SQL, VBA and Python