Heuristics for Integer Programming Using Surrogate Constraints

This paper proposes a class of surrogate constraint heuristics for obtaining approximate, 'near optimal solutions to integer programming problems. These heuris· tics are based on a simple framework that illuminates the character of several carlier heuristic proposals and provides a variety of new alternatives. The paper also pro· poses additional heuristics that can be used either to supplement the surrogate constraint procedures or to provide independent solution strategies. Preliminary compulotional results are reported for applying one of these aJternatives to a class of nonlinear generalized set covering problems involving approximately 100 constraints and 300-500 integer variables. The solutions obtained by the tested procedure had objective function values twice as good as values obtained by standard approaches (e.g., reducing the best objective function values of other methods from 85 to 40 on the average. Total solution time for the tested procedure ranged from ten to twenty seconds on the CDC 6600.