Uniform-machine scheduling problems in green manufacturing system

In this paper, we consider the uniform -machine scheduling problems under the green manufacturing system, in which the newer machine has smaller energy consumption cost. The objective are to minimize the makespan and the maximum lateness under the constrain that the total energy cost has a given upper bound Ub. Considering that these problems are intractable, we assume that the uniform machines have two speeds. For the problems of minimizing the makspan, we first present a polynomial -time algorithm for the twomachine preemptive scheduling problem and then generalize to the m -machine preemptive scheduling problem. Next, we present a 2 -approximation algorithm for the m -machine non -preemptive scheduling problem. Furthermore, for the m -machine non -preemptive scheduling problem of minimizing the maximum lateness, we propose and analyze an improved EDD algorithm.