To design a scheduling expert system under the dynamic environment, one needs to consider not only the performances of tardiness and flow time during the generative scheduling phase, but also the robustness and scheduling time requirements during the reactive control phase. To find the best contingent system's architecture (centralized or hierarchical) in combination with the scheduling strategies on activity ordering, allocation time slot selection, and activity partitioning on multiple parallel machines, a series of experiments have been conducted. The findings can be used to guide the design of scheduling expert systems.