2. Formerly Leicestershire Partnership NHS Trust (Retired). Correspondence c/o first author.

Abstract. Self-healing via a vascular network is an active research topic, with several recent publications reporting the application and optimisation of these systems. This work represents the first consideration of system reliability as a driver in network design. The critical failure modes of a proposed self-healing system based on a vascular network were identified via a Failure Modes, Effects and Criticality Analysis (FMECA) and compared to those of the human circulation system. A range of engineering and biomimetic approaches for addressing these critical failure modes is suggested with minimum system mass the overall design driver for high performance systems. Plant vasculature has been mimicked to propose a segregated network to address the risk of fluid leakage. This approach could allow a network to be segregated into six separate paths with a system mass penalty of only around 25%. Redundant fluid flow paths that mimic the anastamoses of animal vasculatures can be used within a segregated network to balance the risk of failure by leakage and blockage. These biomimetic approaches define a design space that considers several reports from the published literature in the context of system reliability