A class of approximation algorithms is described for solving the minim
um makespan problem of job shop scheduling. A common basis of these al
gorithms is the underlying genetic algorithm that serves as a meta-str
ategy to guide an optimal design of local decision rule sequences. We
consider sequences of dispatching rules for job assignment as well as
sequences of one machine solutions in the sense of the shifting bottle
neck procedure of Adams et al. Computational experiments show that our
algorithm can find shorter makespans than the shifting bottleneck heu
ristic or a simulated annealing approach with the same running time.