An innovative Goddard Space Flight Center methodology for using FMECA as a risk assessment and communication tool

Abstract

Functional and Interface Failure Mode, Effects and Criticality Analyses (FMECA) investigate the following types of detailed potential failure origin and failure impact questions: i) What interfaces dependencies or performance issues exist as a result of each potential functional failure or input loss? ii) If a component fails or exhibits intermittent functionality, is a redundant component available to mitigate the failure effects? iii) If a failure occurs internal to the component's electronics is there the potential for collateral damage of adjacent systems (i.e., Is propagation possible? Will a system failure "Do No Harm" to other systems?)? iv) Can any single failure mode of the instrument lead to total loss of science/data from the instrument or other flight systems? The answers to these questions help to identify Single Point Failures (SPFs), Critical Items, and have the potential to characterize and quantify risk if a risk assessment methodology is used throughout the FMECA process. The following FMECA risk assessment methodology has been developed by GSFC's Reliability and Risk Analysis Branch to assess and communicate failure risks: 1) Correlate Mission Success Requirements-to-GSFC Risk Management Consequence Definitions (GPR 7120.4D); 2) Correlate Failure Severities (NASA/GSFC FMECA Procedures)-to-GSFC Risk Management Consequence Definitions (GPR 7120.4D); 3) Correlate Mission Failure and Duration-to-GSFC Risk Management Likelihood Definitions (GPR 7120.4D); 4) Analyze and characterize each failure mode using these correlations; 5) Assess the Failure Modes as risks, and 6) Communicate risks to mission risk managers. This methodology has already been successfully used on the following NASA GSFC projects: ICESAT-2, OSIRIS-Rex, Robotic Refueling Mission (RRM), Gravity and Extreme Magnetism SMEX (GEMS), and Nuclear Spectroscopic Telescope Array (NuSTAR) to assess and communicate risks including single point failure risks based on FMECA results. Thus it can be considered valid and useable for other missions.