Simulation-based potential analysis of line-less assembly systems in the automotive industry

Increasing product variety, shorter product life cycles, and the ongoing transition towards electro-mobility demand higher flexibility in automotive pro-duction. Especially in the final assembly, where most variant-dependent pro-cesses are happening, the currently predominant concept of flowing line assem-bly is already been pushed to its flexibility limits. Line-less assembly systems break up the rigid line structures by enabling higher routing and operational flex-ibility using individual product routes that are takt-time independent. Hybrid ap-proaches consider the combination of line and matrix-structured systems to in-crease flexibility while maintaining existing structures.
Such system changes require a high planning effort and investment costs. For a risk-minimized potential evaluation, discrete-event simulation is a promising tool. However, the challenge is to model the existing line assembly concept and line-less assembly for comparison.
In this work, a comprehensive scenario analysis based on real assembly sys-tem data is conducted to evaluate the potential of line-less assembly in the auto-motive industry. Within the simulation, an online scheduling algorithm for adap-tive routing and sequencing is used. Based on an automated experiment design, several system parameters are varied full-factorially and applied to different sys-tem configurations. Various scenarios considering worker capabilities, station failures, material availability, and product variants are simulated in a discrete-event simulation considering realistic assumptions. Results show that the throughput and utilization can be increased in the hybrid and line-less systems when assuming that the stations will have failures and the assumption of an un-changed order input.