TY - JOUR

T1 - Two-machine flowshop scheduling with flexible operations and controllable processing times

AU - Uruk, Zeynep

AU - Gultekin, Hakan

AU - Akturk, M. Selim

N1 - Funding Information:
The authors thank to the anonymous referee whose constructive comments improved the quality of the paper significantly. This research is partially supported by the Scientific and Technical Research Council of Turkey under Grant #110M489 .

PY - 2013/2

Y1 - 2013/2

N2 - We consider a two-machine flowshop scheduling problem with identical jobs. Each of these jobs has three operations, where the first operation must be performed on the first machine, the second operation must be performed on the second machine, and the third operation (named as flexible operation) can be performed on either machine but cannot be preempted. Highly flexible CNC machines are capable of performing different operations. Furthermore, the processing times on these machines can be changed easily in albeit of higher manufacturing cost by adjusting the machining parameters like the speed and/or feed rate of the machine. The overall problem is to determine the assignment of the flexible operations to the machines and processing times for each operation to minimize the total manufacturing cost and makespan simultaneously. For such a bicriteria problem, there is no unique optimum but a set of nondominated solutions. Using ε-constraint approach, the problem could be transformed to be minimizing total manufacturing cost for a given upper limit on the makespan. The resulting single criterion problem can be reformulated as a mixed integer nonlinear problem with a set of linear constraints. We use this formulation to optimally solve small instances of the problem while a heuristic procedure is constructed to solve larger instances in a reasonable time.

AB - We consider a two-machine flowshop scheduling problem with identical jobs. Each of these jobs has three operations, where the first operation must be performed on the first machine, the second operation must be performed on the second machine, and the third operation (named as flexible operation) can be performed on either machine but cannot be preempted. Highly flexible CNC machines are capable of performing different operations. Furthermore, the processing times on these machines can be changed easily in albeit of higher manufacturing cost by adjusting the machining parameters like the speed and/or feed rate of the machine. The overall problem is to determine the assignment of the flexible operations to the machines and processing times for each operation to minimize the total manufacturing cost and makespan simultaneously. For such a bicriteria problem, there is no unique optimum but a set of nondominated solutions. Using ε-constraint approach, the problem could be transformed to be minimizing total manufacturing cost for a given upper limit on the makespan. The resulting single criterion problem can be reformulated as a mixed integer nonlinear problem with a set of linear constraints. We use this formulation to optimally solve small instances of the problem while a heuristic procedure is constructed to solve larger instances in a reasonable time.

KW - Controllable processing times

KW - Flexible manufacturing system

KW - Flowshop

KW - Scheduling

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U2 - 10.1016/j.cor.2012.09.001

DO - 10.1016/j.cor.2012.09.001

M3 - Article

AN - SCOPUS:84867399875

SN - 0305-0548

VL - 40

SP - 639

EP - 653

JO - Computers and Operations Research

JF - Computers and Operations Research

IS - 2

ER -