The Optimal Number of Reach Trucks and Order Picker Trucks in Warehouse Determining Using Simulation

The most useful key performance indicator in warehouse operation is the capability of inbound and outbound. The operational report of a case study warehouse shows that the number of inbound and outbound pallets is inconstant and lower than the company target. In order to reach the company target, the optimal number of reach trucks and order picker trucks in the warehouse is required since they are mostly used to move products throughout the process. The procedures firstly start with investigating the warehouse operation process with the current workers' schedule. As a result, the process can be separated into four steps of the inbound process (unloading, checking, moving, and keeping) and two steps of outbound (picking and moving). Then, Tecnomatix Plant Simulation is a the selected tool to create a warehouse operation model and manipulate the number of trucks and workers to achieve the company's target without real process interruption. The theory of constraints and the utilization of workers and trucks from simulation results are used to analyze the process to increase the throughput and eliminate the constraints that limit the warehouse throughput to achieve the company target of 1,300 pallets per day of inbound and 880 pallets per day of outbound. In conclusion, the optimal number of reach trucks and order picker trucks for the case study warehouse target is 5 and 4; respectively.