A revision of some single-machine and m-machine flowshop scheduling problems with learning considerations

Lee and Wu introduce a scheduling model in which the job processing times are affected by both position-based and sum-of-processing-time-based learning effects simultaneously. We demonstrate by a counter-example that their main results are incorrect. We provide a revised model of the general learning effect and show that some single-machine scheduling problems are polynomially solvable under the revised model. We also show that some special cases of flowshop scheduling can be solved in polynomial time under the revised model.