A Heuristic for the Resource-Locking Hybrid Flow Shop Problem in Triaxial Testing

This work addresses the scaling problem of triaxial tests modeled as a Hybrid Flow Shop with resource locking, in which the triaxial cell remains occupied during successive steps of the process. An approach based on Simulated Annealing is proposed to minimize the sum of the test completion times. The methodology is compared to an SPT constructive heuristic and to lower limits obtained by linear relaxation of a Mixed Integer Programming model. The results in eight instances show systematic improvement in relation to the initial solution and gaps of less than 0.5% in relation to the lower limit, indicating that the meta-heuristic produces high quality solutions for practical instances