Scheduling optimisation of a real flexible job shop including fixture availability and preventive maintenance
Artikel i vetenskaplig tidskrift, 2015

The multitask cell at GKN Aerospace Sweden is a flexible job shop containing ten resources aimed at being flexible with regard to product mix and processing types. We present a time-indexed formulation of the problem of optimally scheduling the planned jobs on the resources, also considering a limited availability of fixtures as well as required preventive maintenance activities. The objective is to minimize a weighted sum of the completion times and tardiness for the jobs, where the tardiness weight for a given job is a non-increasing function of its due date. We propose a fast iterative approach to finding a suitable value of the length of the time horizon that needs to be set for the time-indexed formulation and which considerably influences the computation time. Computational results show that the method developed is able to produce optimal, or near-optimal, schedules for real data instances within an acceptable practical time frame.

mathematical optimization

time horizon

production planning

objective weights

flexible job shop scheduling problem (FJSP)

preventive maintenance

dynamic scheduling

fixture availability

time-indexed formulation


Karin Thörnblad

Göteborgs universitet

Chalmers, Matematiska vetenskaper, Matematik

Ann-Brith Strömberg

Göteborgs universitet

Chalmers, Matematiska vetenskaper, Matematik

Michael Patriksson

Göteborgs universitet

Chalmers, Matematiska vetenskaper, Matematik

Torgny Almgren

Göteborgs universitet

Chalmers, Matematiska vetenskaper, Matematik

European Journal of Industrial Engineering

1751-5254 (ISSN)

Vol. 9 1 126-145

Produktionsplanering genom optimal schemaläggning av en multi-taskproduktionscell

Vetenskapsrådet (VR), 2008-01-01 -- 2012-12-31.

GKN Aerospace Sweden, 2008-01-01 -- 2013-10-31.

VINNOVA, 2008-01-01 -- 2013-10-31.


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