Qualitative fault tree analysis applied as a design tool in a low cost satellite design: method and lessons learned
- Paper number
IAC-06-D1.5.07
- Author
Mr. Eddie van Breukelen, ISIS - Innovative Solutions In Space B.V., The Netherlands
- Coauthor
Mr. Rob Hamann, Technical University of Delft (TUDelft), The Netherlands
- Coauthor
Dr. Evert Overbosch, Dutch Space B.V., The Netherlands
- Year
2006
- Abstract
This paper presents the application of Fault Tree Analysis (FTA) in low cost satellite design. The FTA process was tailored for this project as a means to prioritize design and analysis work as well as to evaluate the fault tolerance of the design. Although not nearly as comprehensive as a full Failure Mode Effects and Criticality Analysis (FMECA), the FTA was used early in the design process to increase system reliability and focus such efforts in an efficient way. FTA was introduced at the end of the preliminary design phase of the Delfi-C3 satellite at TU Delft. The purpose of the paper is to evaluate the introduction of FTA in the project and to share lessons learned for everyone involved in similar space projects with tight budgets and short development time. The method that was developed for the circumstances of the project will be shortly described in the paper. From the start of the project in November 2004 much time was spent in discussions on reliability, but this resulted only in a limited overview of reliability and fault tolerance of the design. FTA provided a means to professionalize these discussions and to provide better insight in the reliability aspect of the design. The outcome of the analysis was a qualitative assessment of system reliability for the minimum functionality required, leaving all secondary functionality outside the scope of analysis. With some sidenotes, it was concluded that the current design in general meets the objectives for minimum functionality. For Delfi-C3 this has led to the decision not to perform a full FMECA. It was demonstrated that FTA provides a simple and fast tool to evaluate the effect of design decisions on system reliability. The effectivenesss of the method is illustrated by examples of application. Prioritizing design and analysis work turned out to be the most interesting use of the FTA. Some branches could not be developed far enough, either because design maturity was insufficient for proper modelling, or the specific fault state could better be analyzed by means of another type of analysis. This was indicated in the fault tree and provided an input for the team members responsible for those parts of the satellite. Many of these instances already led to design discussions with responsible team members and corresponding design actions. Furthermore, observations are made on a few factors that affected the acceptance of FTA in the project positively and negatively.
- Abstract document
- Manuscript document
IAC-06-D1.5.07.pdf (🔒 authorized access only).
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