A combinatorial optimization problem consists of finding the minimum s of a function f (economic functions), with real or integer variable on a finite set S, the elements of S verifying certain Optimization is choosing an efficient method capable of producing an optimal solution in a reasonablecomputational time. The different resolution methods developed can be classified into two categories: exact methods which guarantee the completeness of the resolution and approximate methods which lose completeness to gain efficiency. constraints are called feasible solutions; among which, the optimal solution is included..