Abstract
In the 2-Machine Flow Shop problem with exact delays the operations of each job are separated by a given time lag (delay). Leung et al. (Int J Found Comput Sci 18:341–359, 2007) established that the problem is strongly NP-hard when the delays may have at most two different values. We present further results for this case: we prove that the existence of \((1.25-\varepsilon )\)-approximation implies \(\hbox {P}=\hbox {NP}\) and develop a 2-approximation algorithm.
Similar content being viewed by others
References
Ageev, A.A., Baburin, A.E.: Approximation algorithms for UET scheduling problems with exact delays. Oper. Res. Lett. 35, 533–540 (2007)
Ageev, A.A., Kononov, A.V.: Approximation algorithms for scheduling problems with exact delays. In: Approximation and online algorithms: 4th international workshop (WAOA 2006), LNCS 4368, pp. 1–14. Zurich, Switzerland (2007)
Burkard, R.E., Deineko, V.G., van Dal, R., van der Veen, J.A.A., Woeginger, G.J.: Well-solvable special cases of the traveling salesman problem: a survey. SIAM Rev. 40, 496–546 (1998)
Condotta, A.: Scheduling with due dates and time lags: new theoretical results and applications. Ph.D. Thesis (2011). The University of Leeds, School of Computing, pp. 156
Elshafei, M., Sherali, H.D., Smith, J.C.: Radar pulse interleaving for multi-target tracking. Naval Res. Logist. 51, 79–94 (2004)
Gilmore, P.C., Gomory, R.E.: Sequencing a one-state variable machine: a solvable case of the traveling salesman problem. Oper. Res. 12, 655–679 (1964)
Gilmore, P.C., Lawler, E.L., Shmoys, D.B.: Well solved cases. In: Lawler, E.L., Lenstra, J.K., Rinnooy Kan, A.H.G., Shmoys, D.B. (eds.) The Traveling Salesman Problem: A Guided Tour of Combinatorial Optimization, pp. 87–143. Wiley, New York (1986)
Leung, J.Y.-T., Li, H., Zhao, H.: Scheduling two-machine flow shops with exact delays. Int. J. Found. Comput. Sci. 18, 341–359 (2007)
Sherali, H.D., Smith, J.C.: Interleaving two-phased jobs on a single machine. Discret. Optim. 2, 348–361 (2005)
Yu, W.: The two-machine shop problem with delays and the one-machine total tardiness problem, Ph.D. thesis, Technische Universiteit Eindhoven (1996)
Yu, W., Hoogeveen, H., Lenstra, J.K.: Minimizing makespan in a two-machine flow shop with delays and unit-time operations is NP-hard. J. Sched. 7(5), 333–348 (2004)
Acknowledgements
The author would like to thank the anonymous referees for many helpful comments and suggestions.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
This research was supported by the Russian Science Foundation, Grant 17-11-01021.
Rights and permissions
About this article
Cite this article
Ageev, A. Approximating the 2-machine flow shop problem with exact delays taking two values. J Glob Optim 76, 491–497 (2020). https://doi.org/10.1007/s10898-019-00775-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10898-019-00775-0