Minimizing total completion time in the two-machine no-idle no-wait flow shop problem

Abstract

We consider the two-machine total completion time flow shop problem with additional requirements. These requirements are the so-called no-idle constraint where the machines must operate with no inserted idle time and the so-called no-wait constraint where jobs cannot wait between the end of an operation and the start of the following one. We propose a matheuristic approach that uses an ILP formulation based on positional completion times variables and exploits the structural properties of the problem. The proposed approach shows very competitive performances on instances with up to 500 jobs in size.