Efficient and effective warehouse management is one of the most important issues in any supply chain. Order picking, which occurs in a warehouse or distribution center (DC), is the most costly and labor-intensive operation. As a result, many researchers have focused on optimizing this process and finding near-optimal solutions. This study presents a heuristic solution approach to address the order batching and assignment problems in a warehouse with multiple pickers and a central depot. In the proposed method, order batching problem is solved using the proximity batching approach. Additionally, a one-way S-shape routing strategy is implemented, as it is easy for order pickers to follow and reduces congestion in the aisles. In the literature, the majority of studies assume S-shape routing strategy in their solution approach. When assigning batches to pickers, workload balance among pickers is also taken into consideration. The proposed solution approach is applied to both a 6 aisle and 8-aisle warehouse layout. The performance of proposed solution approach is compared with First-Come-First-Served (FCFS) batching method and left-most depot location. The results indicate that constructing a central depot can slightly decrease the order picking distance. However, the followed batching strategy has a much greater impact on order picking performance when compared to the depot location. The proximity batching strategy can significantly reduce the order picking distance when compared to the FCFS batching approach. Furthermore, pairwise comparisons demonstrate that a central depot location with a proximity batching strategy has the most positive effect on increasing order picking performance.