A Study Parallel Machine Scheduling with Consideration of Machines' Power on/off

The usual assumptions in current literature on machine scheduling are the machines are always either available or unavailable for some periods.However,in practice,energy saving and pollution reduction can be achieved by optimizing machines' power on/off.This paper studies a parallel machine scheduling with consideration that neither the length nor the start time of unavailability is fixed.This paper presents a branch and bound algorithm to solve the problem.The computation results show that,within a reasonable computation time,problems with a medium size can be solved to optimality by the algorithm.