Event-based safety and reliability analysis integration in model-based space mission design

Abstract

Model-based safety and reliability (S&R) analysis, which improves analysis accuracy and reduces cost and development time is applied in various industries. With the developments in model-based systems engineering (MBSE) and the use of systems modelling language (SysML), S&R analysis based on SysML models is gaining more attention. However, the emerging methods are inadequate for complex space missions. Thus, the main objective of this study involves integrating S&R analysis in SysML-based space mission design. First, a framework for integrating S&R analysis in model-based space mission design is presented. Based on the characteristics of the development of complex space missions and the MBSE process, a multisystem collaborative failure analysis method is proposed to comprehensively identify the failure modes (FMs) of the entire system. Subsequently, an event-based analysis method integrating the process of functional architecture definition is proposed, which fills the identified gaps in model-based S&R analysis for mission-level systems. Based on the identified FMs and proposed criterion, the event tree can be mapped from the SysML activity diagram. Finally, the proposed methodology is applied to a case study of a complex space mission in the near future: the manned mission to the Moon.