The authors propose an online FMS (flexible manufacturing system) scheduling system that takes into consideration the routing flexibility. A timed Petri net representation of the production system associated with a beam search based decision method is proposed to solve the scheduling conflicts. The system is presented and its performance is evaluated using an example of a FMS with three machines, manufacturing four products with routing flexibility. In addition to its very good results, the system was reliable, as the variance of the results of 50 different simulations was very small.< >