Flowshop Production Scheduling Using the Campbell, Dudek, Smith (CDS), Palmer, and Dannenbring Methods to Minimize the Total Production Time (Case Study: PT. Naturindo Fresh Kulon Progo, Indonesia)

PT. Naturindo Fresh is a company that produces and distributes original Indonesian herbal medicines. The company does not have a planned schedule to minimize the total production time. The production is carried out by considering the products stock and the number of orders from consumers. The employees are free to randomly choose which products will be produced first. The purpose of this research is to determine the job sequence and calculating the total production time (makespan), and identify the sequence that create smallest makespan. The methods used in this research are Campbell, Dudek, & Smith (CDS) method, Palmer method, and Dannenbring method. The calculation results shows that the company's actual scheduling produces a makespan of 30,725.08 minutes. The result of CDS method produces the makespan of 30,634.18 minutes. Palmer's method produces the makespan of 30,743.75 minutes, and the Dannenbring method also yield the makespan of 30,743.75 minutes. In conclusion, the job scheduling with CDS method has the smallest makespan which is recommended to be applied in the company to minimize the total production time.