In this talk, we first discuss simulation-based shop floor planning and control, where 1) on-line simulation is used to evaluate decision alternatives at the planning stage, 2) the same simulation model (executing in the fast mode) used at the planning stage is used as a real-time task generator (real-time simulation) during the control stage, and 3) the real-time simulation drives the manufacturing system by sending and receiving messages to an executor (Finite State Automata). We then discuss how simulation-based shop floor planning and control can be extended to enterprise level activities (top floor). To this end, we discuss the analogies between the shop floor and top floor in terms of the components required to construct simulation-based planning and control systems such as resource models, coordination models, physical entities, and simulation models. Differences between them are also discussed in order to identify new challenges that we face for top floor planning and control. A major difference is the way a simulation model is constructed so that it can be used for planning, depending on whether time synchronization among member simulations becomes an issue or not. We also discuss the distributed computing platform using web services and grid computing technologies, which allow us to integrate simulation and decision models, and software and hardware components. Finally, we discuss other emerging applications for the proposed simulation-based planning and control, such as emergency evacuation and blood supply network.