With the astonishing technological progress in industry during the current epoch, companies are facing a dynamic unpredictable market environment that makes survival to a certain extent difficult for them. Consequently, flexibility seems to be the best approach to enable companies to have an effective response to environmental threats such as economic crisis, growing competitors and market demand fluctuation. Among different types of flexibility, labor flexibility seems to have a determining effect in making a system flexible, since labors are one of the most important resources of a company. This project tries to present a new method to achieve labor flexibility as an effective strategy for garment manufacturing companies that faces market demand fluctuations. The final result of the project shows the proposed algorithms are capable of finding the optimum strategic solution for applying labor flexibility on the production line of the case study.