The improvement of task assignments in a CNC machine station using mathematical models and job dispatching rules: A case study of an automotive parts factory

Abstract

This study focuses on improving the task assignment process in CNC machine workstations to enhance the efficiency of producing automotive parts, such as wheel arches and vehicle chassis. It employs a mathematical model and task sequencing using the Shortest Processing Time, which prioritizes tasks based on their processing time, with the shortest tasks being assigned first. The use of the SPT helps reduce the average time that tasks remain in the system. This study simulates the production process using Excel Solver, incorporating production time data from three CNC machines for comparison between the traditional method and the method with systematic task assignment. The results show that using the SPT reduced the system's job completion time from 70 days under the traditional method to just 52 days with the new approach, representing a 25.71% decrease. Additionally, the total work time was reduced from 1,254 days to 1,048 days, or 16.43%. Furthermore, this task assignment method contributes to a more balanced distribution of workloads across machines, improving machine utilization and allowing for more accurate and systematic scheduling of job deliveries to customers