We consider in this paper the two-machine no-wait flowshop problem in which each machine may have an unavailable interval. We present 3 2 -approximation algorithms for the problem when the unavailable interval is imposed on only one machine, or the unavailable intervals on the two machines overlap. These algorithms improve on existing results.

We introduce a new technique for solving several sequencing problems. We consider Gilmore and Gomory’s variant of the Traveling Salesman Problem and two variants of no-wait flowshop scheduling, the classical makespan minimization problem and a new problem arising in the multistage production process in steel manufacturing. Our technique is based on an intuitive interpretation of sequencing prob...

We study flowshop scheduling problems with respect to slack due window assignments, which are operations in jobs assigned an individual window. We combine learning effect and controllable processing times, the has a two-machine no-wait setup. The goal is determine job sequence, based on common flow allowance, size, resource allocation. provide bicriteria analysis fo...

This paper considers a two-stage flexible flowshop scheduling problem with no waiting time between two sequential operations of a job and no idle time between two consecutive processed jobs on machines of the second stage. We show its complexity and present a heuristic algorithm with asymptotically tight error bounds. © 2004 Elsevier B.V. All rights reserved.