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

Abstract

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.<br>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.<br>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.

Industrial applications of a modular software architecture for line-less assembly systems based on interoperable digital twins

“…To fully exploit the flexibility of the concept of LAS, the DT must base on a modular information model with standardized interfaces for interoperable data exchange allowing the fast integration of new entities (Göppert et al, 2021a). Since the benefits and potentials of the concept of LAS have been investigated and approved in simulations (Schönemann et al, 2015;Hofmann et al, 2019;Buckhorst and Schmitt, 2020;Hüttemann, 2021;Rachner et al, 2022b), current research is concerned with the implementation of LASs as a cyber-physical production system (CPPS). CPPS consists of intelligent and connected assets and subsystems that acquire information from their production environment and act autonomously in response to internal and external changes in the production system (Monostori et al, 2016).…”

“…To satisfy the criteria of interoperability, the DTs are evolved following the methodology of the Digital Twin Pipeline introduced by (Göppert et al, 2021a). As part of the research project "AIMFREE" (Rachner et al, 2022a), a LAS demonstrator is built and installed where several variants of a car's drive battery module are assembled. Following the production paradigm of line-less assembly, the CPPS consists of multiple partially automated assembly stations connected by AGVs that handle all logistics processes.…”

Agile, frei verkettete Montage real erleben/Experiencing an agile, line-less assembly

“…Bisher wurden die Potenziale der agilen, frei verketteten Montage meist durch Simulationen untersucht (wie in [5][6][7]…”