This paper investigates a real world assignment problem, which slightly dif
fers from the classical generalized assignment problem (GAP). The large-sca
le number of variables in the related 0-1 linear program makes the use of c
ommercial optimization packages impractical. We present here a metaheuristi
c using simulated annealing. It is based on successive reductions of the se
arch space by identification of locally active constraints. Our approach em
ploys a heuristic procedure to compute an initial (feasible or infeasible)
0/1 solution, and a double-criterion acceptance rule. The performance of th
e algorithm is demonstrated on real data sets.