A Direct Proof of the 4/3 Bound of LPT Scheduling Rule

Abstract

Abstract. The problem of scheduling independent jobs on identical parallel machines for minimizing makespan has been intensely studied in the literature. One of the most popular constructive algorithms for this problem is the LPT (Longest Processing Time First) rule whose approximation ratio has been proved by contradiction. A direct proof of its approximation ratio is presented, which can be regarded as an acquisition of knowledge by deductive means.