Two-machine flowshop scheduling with flexible operations and controllable processing times
Date
2013Source Title
Computers and Operations Research
Print ISSN
0305-0548
Electronic ISSN
1873-765X
Volume
40
Issue
2
Pages
639 - 653
Language
English
Type
ArticleItem Usage Stats
136
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127
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Abstract
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.
Keywords
Controllable processing timesFlexible manufacturing system
Flowshop
Scheduling
Bicriteria problems
CNC machine
Controllable processing time
Feed-rates
Flexible operation
Flow-shops
Heuristic procedures
Identical jobs
Linear constraints
Machining parameters
Makespan
Manufacturing cost
Mixed integer nonlinear problems
Nondominated solutions
Processing time
Two-machine flowshop
Upper limits
Computer control systems
Flexible manufacturing systems
Heuristic methods
Scheduling algorithms
Scheduling