This paper presents a model of a Goods-to-Person (GTP) system that incorporates a Shuttle-Based Storage and Retrieval System (SBSRS) and develops a simulator to evaluate its performance. The proposed model facilitates a comparative analysis of independently applied operational rules across the shuttle, elevator, and loop subsystems. The primary objective is to gain insights into effective combinations of operational decision-making rules that improve the utilization of picking stations through simulation-based experiments. As an initial step, we computationally compare the round-robin order assignment rule, the conventional First-In First-Out (FIFO) rule, and newly proposed rules for both order assignment and transportation sequencing within the loop system using the developed simulator. The results show that variations in the decision-making rules of each subsystem influence the utilization rates of the picking stations. This indicates that overall system performance can be optimized by appropriately combining the decision-making rules across subsystems.