Integration of hierarchical layers corresponding to operation of Batch Chemical Plants has become an area of increasing interest in recent years [1]. The use of on-line scheduling strategies to accommodate the schedule to real-time disturbances, due to the uncertain nature of chemical processes, facilitates the coordination between high production scheduling and low sequential control activities. This paper focuses on the development of a reactive scheduling algorithm based on the generation of multiple search trees. The best solutions are selected according to heuristic rules which are adjusted to each case analyzed. Changes of tasks start times and unit reassignment are considered. Finally, a case study is presented and results are discussed.