Obsolescence and Availability: The Hidden Challenges of Complex Systems

The obsolescence challenges associated with rapid technological advances have a significant impact on the overall performance of complex, long-life systems, particularly in sectors such as transportation and heavy industry. This paper addresses these challenges by modeling how obsolescence impacts system availability, reliability, and maintainability considering different categories of item: Make/Buy Repairable and Make/Buy Consumable. Each category encompasses distinct failure, fault and replacement scenarios, which are analysed using flow diagrams. The proposed models provide a systematic understanding of obsolescence mechanisms, including inventory management strategies, repair or replacement paths, and supplier interactions. They also address the progressive decline in availability caused by the obsolescence of components, tools, documentation and technical soft skills. The paper contributes a structured modeling approach based on flow diagrams that links obsolescence scenarios to maintenance decisions, helping anticipate and mitigate performance degradation. By clarifying the decision-making processes inherent in each scenario, the study improves the understanding of the impact of obsolescence on system performance. The article ends with findings and research on predicting system availability under obsolescence.