abstract = "Dynamic flexible job shop scheduling (DFJSS) is one of
the well-known combinational optimisation problems,
which aims to handle machine assignment (routing) and
operation sequencing (sequencing) simultaneously in
dynamic environment. Genetic programming, as a
hyper-heuristic method, has been successfully applied
to evolve the routing and sequencing rules for DFJSS,
and achieved promising results. In the actual
production process, it is necessary to get a balance
between several objectives instead of simply focusing
only one objective. No existing study considered
solving multi-objective DFJSS using genetic
programming. In order to capture multi-objective nature
of job shop scheduling and provide different trade-offs
between conflicting objectives, in this paper, two
well-known multi-objective optimisation frameworks,
i.e. non-dominated sorting genetic algorithm II
(NSGA-II) and strength Pareto evolutionary algorithm 2
(SPEA2), are incorporated into the genetic programming
hyper-heuristic method to solve the multi-objective
DFJSS problem. Experimental results show that the
strategy of NSGA-II incorporated into genetic
programming hyper-heuristic performs better than
SPEA2-based GPHH, as well as the weighted sum
approaches, in the perspective of both training
performance and generalisation.",