KAUSAL - Transparent Modelling of Causal Chains regarding Failure Development in Complex Systems

• Applicant: Professorin Dr.-Ing. Petra Winzer
• Subject Area: Engineering Design, Machine Elements, Product Development ; Production Systems, Operations Management, Quality Management and Factory Planning
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 282754305

Due to high wage costs and incidental wage costs Germany has no opportunity to beat competitors prices from low-wage countries. As the price cannot be the compelling argument for buying our products, it is essential for industrial companies to hold what the Made in Germany seal promises. But prominent examples impressively demonstrate that our existing methods for failure analysis and failure prevention are no longer sufficient. There are two relevant failure categories: On the one hand, subsystems meet their specifications, if they are considered individually. But the overall system, which combines multiple subsystems is not functioning properly, e.g. due to compounding tolerances. On the other hand, a subsystem is not okay and affects other subsystems as well as the overall system. Recent approaches in terms of industry 4.0 identify those problems, but adhere to component-based or module-based analysis. They do not consider that a system is more than the sum of its subsystems. As the complexity of modern products increases, their development requires experts from various engineering disciplines. In combination with numerous customer-supplier relations, in which system suppliers take over the development of components and subsystems, failures are difficult to trace. This is especially the case, when failure causes and consequences distribute to multiple system levels. Considering these issues, the project KAUSAL strives to establish a holistic methodology for product development of complex systems in industrial companies. The resulting methodology shall not restrict the length of causal chains of failure emergence and it shall be convenient to depict malfunctions in addition to failures. Causal chains are analyzed across the boundaries of engineering disciplines and subsystems in order to develop integral resolutions. Within the project a standardized system model will be elaborated using product examples from the fields of electromobility, intralogistics and renewable energies. This system model serves as structured information pool for the causal chains. Basing on this model, failures and malfunctions will be formulated systematically and integrated into a causal chain model. Subsequently, techniques for qualitative and quantitative evaluation from established reliability methods will be applied on the causal chains. Result of the project is a validated KAUSAL-methodology, which is suitable to trace potential failures and malfunctions regarding their causes and consequences on various system levels. Transparent depiction of failures enables a better system understanding and serves as basis for discussions between the engineering disciplines as well as customers and suppliers.

• DFG Programme: Research Grants