Erratum to “A discrete colonial competitive algorithm for hybrid flowshop scheduling to minimize earliness and quadric tardiness penalties” [Expert Syst. Appl. 38 (2011) 14490–14498]

In this note, we point out that the mixed integer programming model of a hybrid flowshop scheduling problems presented by Behnamian and Zandieh [Expert Syst. Appl. 38 (2011) 14490–14498] is incorrect. We also point out that some responses from the authors are mistake.