An online scheduling algorithm for equal and concurrent batch process units embedded in a large process is shown in this paper. Its target is to calculate the waiting time intervals between consecutive cycles of each batch process unit to achieve a global stationary scheduling. This approach is based on nonlinear model predictive control with heuristic constraints for the particular process. The algorithm has been tested against an industrial problem simulation that consists of a set of batch sugar crystallizers which are part of a reduced sugar production process. Due to the large computational load of the optimization procedure, a reduced prediction model of the system was developed to obtain real time solutions. (C) 2019 Elsevier Ltd. All rights reserved.