A new model for multi-purpose scheduling problem (MSP) in batch process with parallel units was presented. The variables of this model were the sequence of order process steps and order assignment rules in each stage. New strategies of individual representation and mutation in the line-up competition algorithm were proposed to solve the model effectively. Computational results showed that the efficiency of the proposed approach was superior to the method reported in literature and obtained better result

especially

for complex MSP with parallel units. This approach demonstrated promising performance in solving large-scale complex MSP.