In this paper, we propose a rule-based reactive rescheduling system to cope with several unexpected process events for multi-purpose batch process operations. The developed system consists of two major modules. The first module continuously monitors production status whether a processing task starts at the scheduled starting time and completes at the scheduled ending time. When a deviation from the initial schedule is detected by the first module, a delay index defined in this research is evaluated to determine whether the second module must be activated. The delay index is used to measure the effect on the remain scheduled operations by several unexpected events. If the second module is tired, it determines appropriate actions to minimize the effect of the event on the remaining initial schedule. Here, all process components in a plant are described by object-oriented programming paradigm.