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Approximation algorithms for two-machine flow shop scheduling with an outsourcing option

CHEN GuangtingCHEN LeiZHANG An1,*   CHEN Yong1   

  1. 2.  School of Science, Hangzhou Dianzi University, Hangzhou 310018, China
  • Received:2016-02-01 Online:2016-12-15 Published:2016-12-15

Abstract:

The paper investigates flow shop scheduling with an outsourcing option. The objective is to minimize the sum of the in-house cost and the outsourcing cost, where the in-house cost is measured by the maximum completion time of jobs. We design approximation algorithms to solve the problem. For two-machine flow shop, we provide an algorithm with a worst case ratio of 2. For two-machine ordered flow shop, we give an improved algorithm with worst case ratio \frac{3}{2}. Both ratios are tight.

Key words: outsourcing option, flow shop, approximation algorithm, worst case analysis