A rounding algorithm for altemate machine scheduling

대안기계 스케쥴링 문제에 대한 라운딩 알고리듬

In this paper we consider alternate m machine scheduling problem in which each job having at most two eligible machines should be assigned with the objective of makespan minimization. For this problem, we propose a $O(m2^m)$ time rounding algorithm with performance ratio at most 1.5. For a little general problem where each job can be processed at most three machines, we prove that there cannot exist a polynomial time algorithm with performance ratio less than 1.5.