Scheduling is an important part of the production process. Flow shop scheduling is a continuous movement of units through a series of work stations arranged based on products. PT. Paku Gajah Mas is an industrial manufacturing company that produces various sizes of nails. Orders are produced according to incoming orders and have a First Come First Serve scheduling system. Scheduling in PT. Paku Gajah Mas is still not optimal due to frequent delays in orders reaching the buyer. The data used in this research is demand data for August 2020. This study aims to find the best scheduling by finding the smallest makespan value of each proposed method. The methods used in this research include the CDS method, the Genetic Algorithm, and the Bat Algorithm. Based on the analysis, it was found that the best scheduling method with the smallest makespan value for PT. Paku Gajah Mas uses a genetic method with the results of 488.16 minutes makespan and an increase of 7.35% from the current scheduling time