This study examines the impact of different circular shell and tube heat exchanger configurations on the system charging time. Various configurations will be evaluated, namely A, B, C, and D, with 1, 2, 3, and 4 tubes, respectively. The shell contains a phase change material (N‐eicosane), and the location of tubes changes in each configuration, forming a new case. A total of 38 numerical experiments were conducted using a commercial software to investigate various tube locations and arrangements. While previous studies have primarily focused on total charging time as the fitness measure for different configurations, this study considers the need to achieve high charging levels within limited time windows. Therefore, a configuration that takes longer to charge completely may have a shorter time to reach 90% of charging, making it more reliable. The top configurations were assessed with gold, silver, and bronze rankings based on their agility to reach milestones (at every level of 50%, 80%, and 90% charging). For instance, case C6 achieved a golden ranking for reaching 90% of full charge in about 328 seconds, 12.5% faster (41 seconds) than the efficient configuration (C5) with the minimum total time. However, C6 has a longer total charge time of 516 seconds (about 20% extra time). On the other hand, C5 also has the fastest time for reaching milestones at 50% and 80% of charging, which shows that it responds to the thermal source very rapidly. The results also demonstrate that increasing the tubes significantly decreases total melting time. For instance, the efficient case of type D, D7, takes only about one‐fifth (80% improvement) of the total charging time compared to the base case, A1. Finally, the performance of various cases during the discharge process is also evaluated.