Stabilsation of assembly systems in ramp-up

• Applicant: Professor Dr.-Ing. Robert Heinrich Schmitt
• Subject Area: Production Systems, Operations Management, Quality Management and Factory Planning
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 471703091

Instability in production systems and processes is a characteristic of production ramp-ups. These instabilities do not allow production conditions to be reproduced, so that the targets of a ramp-up are missed due to stochastically occurring losses. The objective of this research project is to ensure the quality and quantity performance of a ramping up assembly system by means of a continuous, quality-oriented evaluation and adaptation of the ramp-up strategy during the ramp-up of an assembly system. A design model will be developed to plan and accompany the production ramp-up. In the planning phase, the design model provides the possibility of simulating the production ramp-up for various ramp-up strategies and under the specific conditions of the assembly system and the specified ramp-up targets. The simulation provides a forecast of the ramp-up performance at different points in time, allowing the control variables to be optimally adjusted during the ramp-up planning phase and an initial ramp-up strategy to align the production ramp-up can be derived. During ramp-up, the control variables are superimposed with real disturbance variables. The resulting variables are fed back into the design model as additional information and cause an improvement in the simulation results. By applying methods for solving nonlinear optimization problems to the simulations, recommendations for adjusting the ramp-up strategy are derived. The adaptation brings an unstable or an assembly system that tends to instability into a stable state of equilibrium. In a stable state of equilibrium, the deviations of the operating results behave naturally and the ramp-up of production is characterized by reproducible conditions, which enable the realization of planned unit costs and operation under normal productivity.

• DFG Programme: Research Grants