Fall-Back Analysis using Model-Based Engineering

Mission Assurance is a discipline which aims to identify and mitigate technical risk that can impact mission success. Fall-Back Analysis (FBA), a technique proposed by PHM Technology, supports Mission Assurance objectives by identifying alternate pathways (Workarounds) for a function to be successfully executed by a system if a critical component experiences a Functional Failure.Model-based simulation and analysis of Reliability, Safety and Diagnostics allows FBA to be performed concurrently during the design process - increasing the likelihood of mission success. The concepts behind FBA are not new (e.g. loss of oxygen tank on the Apollo 13 and the resultant ‘workaround’, and large-scale industry projects on offshore oil and gas rigs/platforms), but what is novel is formalizing this approach into a methodology that can be readily applied by leveraging outputs from model-based Mission Assurance.This paper uses the MADe modelling environment to identify potential component Functional Failure Modes and conduct Fall-Back Analysis to ensure mission functions can still be satisfied.