ISBN 978-3-8439-2241-8

978-3-8439-2241-8, Reihe Produktentwicklung

Thierry Sop Njindam
A Systemic Approach to Analyze Failures of Complex Multidisciplinary Systems on the Basis of their Weak Emergent Behaviour

200 Seiten, Dissertation Universität der Bundeswehr München (2015), Softcover, A5

Zusammenfassung / Abstract

Over the last few decades, technological systems have experienced an unprecedented increase of their functionality through the steady integration of electronics, information technology and software engineering, turning them into self-aware multidisciplinary systems with nonlinear autonomous behaviour and the ability to interact with their surroundings. This paradigm shift is nevertheless a double-edged sword; on the one hand it leads to an added value due to the enhancement of functionality and performance of modern technological systems by blurring the boundaries between individual technical disciplines. On the other hand, it inevitably increases their complexity and thus their susceptibility to failures. To solve this issue, new systemic concepts and methods are needed to increase the understanding of complexity features e.g. unforeseeable emergent properties, which evolve in engineered systems and can have harmful effects on the system functionality at a macroscopic level.

So far, the preventive analysis of system failures has been characterized by reductionist deterministic assumptions relying on the linear-causal effects between single components failures and the inability of systems to function properly. Investigations which are provided in various literatures have shown that the emergent properties of a system that stem from nonlinear interactions and which cannot be predicted with certainty, have been ignored as root causes for system failures. Building on this, the unpredictability of emergent properties has been integrated in the model-based systems engineering of complex multidisciplinary systems, as their failures are not only induced by single failure of their critical elements but also by the poor understanding of the interactions among their constituent elements, even without any single part failing. This thesis aims at providing an understanding of the emergent behaviour of complex multidisciplinary systems in early design stages, by particularly focusing on interactions among system elements and with their surroundings. Based on the analysis of interactions between their heterogeneous elements, a categorization of emergent properties of complex multidisciplinary systems as a causal factor of system failures is proposed. In this respect, a taxonomy of complex system failures is suggested.