September 2020 Newsletter
ASCA is now halfway through its two-year SBIR project. The team is working with NASA on deploying our safety methodology in future autonomous space systems. We are now looking for a partner so we can demonstrate how to use our software for safety analysis of autonomous cars.
Dynamic Flowgraph Methodology (DFM) Modeling of Nuclear and Advanced Technology System Risk and Reliability Scenarios
Probabilistic safety assessment (PSA) is the standard method for assessing and improving safety of nuclear power plants. Shutdown PSA is a version that has been developed relatively later compared to that associated with the assessment of plant power operation. Many common features and some differences exist between power PSA and shutdown PSA. The main PSA […]
Dynamic Probabilistic Risk Assessment of Unmanned Aircraft Adaptive Flight Control Systems
There is a great demand for risk assessment tools and techniques that can ensure safe and robust performance of an Unmanned Aircraft System (UAS) equipped with adaptive elements in missions involving multiple phases with uncertain system or operational conditions. A dynamic probabilistic risk assessment scheme involving multiple phase-specific implementations of a Backtracking Process Algorithm (BPA) […]
Risk Informed Safety Case Framework for Unmanned Aircraft System Flight Software Certification
The rapid growth in availability and use of Unmanned Aircraft Systems (UAS) brings with it safety questions and significant challenges to the Federal Aviation Administration (FAA) and the aviation community. One of the key questions and challenges concerns the integration of UASs into the National Airspace System (NAS) and the path, criteria and processes that […]
Formal Framework and Models for Validation and Verification of Software- Intensive Aerospace Systems
Model-based control systems (MBCSs) and adaptive control systems (ACSs) represent an emerging class of software-intensive space and aeronautical control applications that bring tangible benefits to design processes and developments, but also challenges to traditional validation and verification (V&V) methods. This paper presents the results produced in the first two years of a three-year NASA project […]
Context-Based Software Risk Model (CSRM) Application Guide
This paper discusses ASCA’s experience in applying the Dynamic Flowgraph Methodology (DFM) to a space propulsion system problem specified by the Idaho National Laboratory (INL). This problem serves as a benchmark for comparing and evaluating the capabilities of advanced Probabilistic Risk Assessment (PRA) tools that are suitable for the risk analysis of future space systems. […]
