TY - GEN

T1 - Minimizing the Makespan in flowshops with flexible operations

AU - Demirtas, Hatice Hande

AU - Gultekin, Hakan

N1 - Funding Information:
⋆ This study is supported by the Scientific and Technological Council of Turkey under grant # 110M489.

PY - 2012

Y1 - 2012

N2 - We consider a flowshop with m machines each of which perform a specific operation of the identical parts to be processed. Two specific adjacent machines among all machines are capable of performing an additional operation required by each part, which is named as the flexible operation. The problem is to decide on the machine to perform this flexible operation for each of the n parts to be processed. The assignment can be different from one part to another. Therefore, although the parts are identical, their actual processing times on the machines can be different from each other. The objective is to minimize the makespan. One application of such production systems can be found in metal cutting industries where highly flexible CNC machines are used. These machines are capable of performing different operations as long as the required cutting tools are loaded on the tool magazines. Similar problems also exist in assembly lines with human operators where the workers are cross-trained. We first formulate the problem as a mixed integer program and determine some properties of the optimal solutions. We identify some special cases of the problem where it can be solved trivially. For the remaining cases we develop a heuristic algorithm and test the efficiency of this algorithm through a computational study. The results of this analysis indicate that the developed heuristic is very efficient in terms of both solution quality and the required CPU time.

AB - We consider a flowshop with m machines each of which perform a specific operation of the identical parts to be processed. Two specific adjacent machines among all machines are capable of performing an additional operation required by each part, which is named as the flexible operation. The problem is to decide on the machine to perform this flexible operation for each of the n parts to be processed. The assignment can be different from one part to another. Therefore, although the parts are identical, their actual processing times on the machines can be different from each other. The objective is to minimize the makespan. One application of such production systems can be found in metal cutting industries where highly flexible CNC machines are used. These machines are capable of performing different operations as long as the required cutting tools are loaded on the tool magazines. Similar problems also exist in assembly lines with human operators where the workers are cross-trained. We first formulate the problem as a mixed integer program and determine some properties of the optimal solutions. We identify some special cases of the problem where it can be solved trivially. For the remaining cases we develop a heuristic algorithm and test the efficiency of this algorithm through a computational study. The results of this analysis indicate that the developed heuristic is very efficient in terms of both solution quality and the required CPU time.

KW - Flexible manufacturing systems (FMS)

KW - Line design and balancing

KW - Scheduling heuristics

UR - http://www.scopus.com/inward/record.url?scp=84866083754&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84866083754&partnerID=8YFLogxK

U2 - 10.3182/20120523-3-RO-2023.00093

DO - 10.3182/20120523-3-RO-2023.00093

M3 - Conference contribution

AN - SCOPUS:84866083754

SN - 9783902661982

T3 - IFAC Proceedings Volumes (IFAC-PapersOnline)

SP - 1366

EP - 1370

BT - Proceedings - INCOM'12, 14th IFAC Symposium on Information Control Problems in Manufacturing

PB - IFAC Secretariat

T2 - 14th IFAC Symposium on Information Control Problems in Manufacturing, INCOM'12

Y2 - 23 May 2012 through 25 May 2012

ER -