Dynamic tolerance allocation and application of quality control cycles or high-precision products in production ramp-up

• Applicants: Professorin Dr.-Ing. Gisela Lanza; Professor Dr.-Ing. Sandro Wartzack
• Subject Area: Production Systems, Operations Management, Quality Management and Factory Planning ; Engineering Design, Machine Elements, Product Development
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 549526281

High product quality is not only a central customer requirement but also a decisive factor for economic success in international competition. This is particular valid for filigree high precision products. Since production processes are on the edge of technical feasibility, the tolerance allocation plays a critical role, because too tight tolerances lead to significantly increased manufacturing costs or are impossible to manufacture with required process reliability. In contrast, too wide tolerances may lead to malfunctioning of the product and bad quality. Conventional statistical approaches, which are typically used in tolerance analysis and tolerance synthesis, cannot be applied for the virtual validation of high precision products, since they imply steady state processes. Motivated by this, methods for the dynamic tolerance allocation in product design and quality control, which integrate current information and measurement data from production by means of digital twins of the product and production process considering inherent uncertainties, are to be investigated in this research project. Particularly, the focus is on the ramp-up of production with the aim to increase the product quality and the first application rate. Moreover, methods for the short cyclic increase of product quality will be developed and applied to a case study. These works will lead to a holistic approach for the quality improvement, which comprises situative strategies based on a combination of adaption of tolerance types and values and quality control. At the end of the project, transferable methods are developed and validated, which allows assessing their applicability to various problems of industrial complexity. The research project requires know-how from two distinct research domains. On the one hand, the knowledge about the holistic development and assessment of production systems is necessary. On the other hand, experience regarding the statistical tolerance simulation and tolerance allocation is indispensable. Moreover, expertise concerning the application of digital twins for products and production systems is required.

• DFG Programme: Research Grants