DEVELOPMENT OF ASSEMBLY LINE AND OPERATOR ASSIGNMENT MODELS CONSIDERING CLASSIFICATION OF OPERATORS IN FINAL ASSEMBLY LINE

• Main Author: Prijo Utomo, Rudy
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/36759
• Institution: Institut Teknologi Bandung

The assembly line in Final Assembly Line (FAL) currently uses the fixed layout concept with 4 stages (post). A stage has several operations, and each operation needs exact classification of operators to process it. To meet orders for type-Y aircraft, FAL usually delay in delivery to the next PT.X internal customer, the Delivery Center (DC). The Key Performance Indicator (KPI) reported the average value of FAL Department for a Cycle Time, reached 690%. This value is too far from the objective of the KPI, ? 100%. Even though the FAL is currently targeted to meet the demand of 4 aircrafts/year, it needs an effort to reach a 3 months cycle time. An assembly line model needs to be designed to manage the assignment of operators, and balance the workloads. The proposed model is an analytical model of Mixed Integer Linear Programming (MILP). The objective function of this model is to minimize the makespan, with the inputs are demand and time data available, operating data, operators data and precedence diagrams. And the outputs are operating placement on the work station, operator assignment on operations, start time of each operation, and last operation start time. To achieve the production target of 4 aircraft units/year, the solution of the proposed model produces an assembly line with 4 work stations. The proposed model reduces makespan from 16 months to 8.7 months and do a 293 hours (less than 3 months) of cycle time. This solution model also able to reduce the number of operators, from 83 operators to 77 operators. The computational results also show that the model is able to produce assembly lines that are better than the existing conditions, this is indicated by the increasing line efficiency from 62.67% to 96.5% and decreasing the smoothness index value from 733.48 to 28.51.