A schedule management system 1 having isolators 3 (production facilities) and a main control device 4 for managing a production schedules of all the isolators 3.

The production process of each isolator constituting the production schedule has a plurality of sub-processes, the production status being determined in the sub-process.

The main control device 4 adds a new separating operation to the passage process and performs an update when the main control device 4 obtains a determination result that the separation of cells in a separation state confirmation operation (sub-process) in the passage process is insufficient while a passage process for cells A is being carried out in the isolators.

The main control device 4 alters the start time of a culture medium exchange process for other cells B different from the updated passage operation, and updates the production schedule.

Since single and dual-arm tools behave differently, it is difficult to coordinate their activities in a hybrid multi-cluster tool that is composed of both single- and dual-arm tools. Aiming at finding an optimal one-wafer cyclic schedule for a treelike hybrid multi-cluster tool whose bottleneck tool is process-bound, the present work extends a resource-oriented Petri net to model such system. By the developed Petri net model, to find a one-wafer cyclic schedule is to determine robot waiting times. By doing so, it is shown that, for any treelike hybrid multi-cluster tool whose bottleneck tool is process-bound, there is always a one-wafer cyclic schedule. Then, computationally efficient algorithms are developed to obtain the minimal cycle time and the optimal one-wafer cyclic schedule. Examples are given to illustrate the developed method.