In this paper, we consider the problem of mapping rules in a production system onto nodes in a multiprocessor system. Since this problem is NP-hard, we present an efficient heuristic algorithm based on simulated annealing to solve this mapping problem. Compared to conventional simulated annealing algorithms to solve this problem, where moves or exchanges are used exclusively as perturbation functions, we use a combination of moves and exchanges to achieve consistently better solutions in a reasonable amount of computation time. Further, by restricting the random acceptance of configurations (mappings) during the annealing process, we achieve a faster convergence. We demonstrate the effectiveness of our algorithm by comparing its performance with that of another recently proposed algorithm for mapping rule based systems onto multiprocessors.