Makespan Minimization for Two Parallel Machines Scheduling with a Periodic Availability Constraint: The Preemptive Offline Version

We consider the preemptive offline version of the problem "two parallel machines scheduling where one machine is periodically unavailable with non-preemptive jobs and the objective of minimizing the makespan." We propose a polynomial algorithm with time complexity O(n log n) based on the well-known McNaughton' Wrap-Around rule for the considered problem.