Résumé en anglais

The purpose of this paper is mainly to prove the following theorem: for every polynomial time algorithm running in time T(n) and guaranteeing standard-approximation ratio varrho for bin-packing, there exists an algorithm running in time O(nT(n)) and achieving differential-approximation ratio 2 − varrho for BP. This theorem has two main impacts. The first one is “operational”, deriving a polynomial time differential-approximation schema for bin-packing. The second one is structural, establishing a kind of reduction (to our knowledge not existing until now) between standard approximation and differential one.