1. A method for scheduling cars of an elevator system, comprising the steps of: representing each possible assignment of a set of hall calls to a set of cars by a solution vector maintained as a node in a search tree; evaluating each solution vector using an ESA-DP process according to an immediate policy to determine initially a best solution; and applying a branch-and-bound process to each solution vector using the initial best solution and the search tree to determine a globally optimal solution for scheduling the cars according to an reassignment policy.