Model Based Approach for RAMS Analyses in the Space Domain with Capella Open-Source Tool

Abstract

The objective of this paper is to evaluate the interest and applicability of a Model Based approach to support Dependability engineers in performing RAMS (Reliability, Availability, Maintainability and Safety) analyses.

In order to address the future challenges of the Space domain and to improve the co-engineering activities during the whole spacecraft design process, the open-source Capella tool, based on the Arcadia methodology, has been recently envisaged and evaluated in Thales Alenia Space.

Capella can already support Model Based System Engineering (MBSE) activities: from requirement specification to physical architecture definition, through functional and logical analyses. The MBSE approach has already demonstrated its benefits for System Engineering activities since it enhance the ability to capture, to analyze, to share, and to manage the information associated with the complete specification of a product.

Some features are currently being implemented in Capella in order to support also dependability activities. The Model Based RAMS approach with Capella is expected to improve the co-engineering activities between system engineers, equipment experts and dependability responsible. This will in turn improve the current Quality Assurance process, which is indispensable for the futures space missions.

The preliminary applications of the Model Based approach for RAMS analyses have shown some possible limitations and axes of improvements that will be addressed by future studies.