Relevant ongoing or recently-completed ASCA, Inc. projects are listed below.

Development of NASA Probabilistic Risk Assessment Procedure Guide and Training Courses

NASA Headquarters

This project sponsored by NASA Headquarters Code-Q is in cooperation with a team of other organizations. It has the objective of compiling a state-of-art guideline document for the application of Probabilistic Risk Assessment (PRA) procedures and techniques within the entire NASA enterprise and contractor community. Along with the Guide, training course materials are also being developed to assist NASA Centers and Contractors in the use of the Guide.

Mars Exploration Missions Safety and Risk Assessment

Jet Propulsion Laboratory / NASA

This project was initiated in 1998 and continues under contract to the NASA Jet Propulsion Laboratory. It has the objective of developing and applying risk assessment methodology for the launch vehicle and spacecraft segments of various solar system exploratory missions. Included in the larger scope of the project, which covers a span of several years, is methodology development and refinement, software tool development and actual execution of the safety and risk analysis. In this project ASCA is interacting and cooperating regularly with various organizations that have responsibility for interfacing aspects of the overall risk assessment process, within a team which includes Department of Energy and NASA contractors. Into these activities ASCA brings its expertise and databases in the areas of launch and space vehicle reliability, safety and mission assurance analysis.

New Horizons Pluto and Kuiper Belt Mission Safety and Risk Assessment

Johns Hopkins University Applied Physics Laboratory / NASA

This project was initiated in 2001 and presently is in progress, under contract to the Johns Hopkins University Applied Physics Laboratory. It is similar in objective and scope to the project carried out for the Jet Propulsion Laboratory in relation to the nuclear safety of the Mars Exploration Program missions, which is described above. This project is expected to continue for one or two additional years, depending on the final launch date decisions made by NASA jointly with the Johns Hopkins University Applied Physics Laboratory, its prime contractor for the Pluto mission.

Automated FMECA and Diagnostic / Prognostic Optimization Analysis

Patuxent River Naval Air Warfare Center Aircraft Division / U.S. Navy

This project explored the development of diagnostic/prognostic techniques for rotorcraft turbine engines and gearboxes. The developments achieved in this projects are based on a combination of model-based, multi-state diagnostic / logic framework and statistical inference models, which implement optimization principles based on maximization of risk reduction and minimization of life-cycle cost. Full development of the modeling framework and associated software tools will follow at a later stage.

Aircraft Probabilistic Risk Assessment Methodology (APRAM)

U.S. Department of Transportation, Federal Aviation Administration

This project identified tailored Probabilistic Risk Assessment (PRA) techniques to address airplane design and air-transportation risk issues brought about by the rapid advancement of technology in the airplane industry. Tools and techniques that can be used by safety analysts to evaluate the operational and safety risk impacts of specific scenarios or technology conditions, and by designers to understand the risk-benefit trade-offs that technological innovations or conditions may produce, were identified and preliminarily demonstrated. This work has laid out the path for the development of a risk assessment software tool package that could be used by aircraft manufacturers and major airlines to demonstrate the safety of existing aircraft and/or the safety of new systems proposed in new designs or design upgrades. This tool would also be used to evaluate concept and design alternatives in a risk-reduction worth versus cost basis.

Application of Dynamic Flowgraph Techniques for Safety Analysis and Testing of Space Systems Software

National Aeronautics and Space Administration, Glenn (formerly Lewis) Research Center

This project applied the analytical assurance procedures of the Dynamic Flowgraph Methodology (DFM) and the associated software tools to a system which is representative of software-controlled systems of interest to NASA for its satellite, spacecraft or ground-support systems applications. Executed tasks include 1) demonstration of the applicability of DFM analysis to NASA space systems, 2) refinement and optimization of DFM procedures for NASA space systems software applications and 3) integration and demonstration of the extended and optimized DFM technique on a NASA space system case study. The case study used was space experiment apparatus and associated controls which was part of a Space Shuttle mission. The project included the development of techniques to define specific software test vectors that can be used to verify whether various types of software faults are present in an integrated system.

Development of Tools for Software Safety Analysis in Space Systems Applications

National Aeronautics and Space Administration, Johnson Space Center

This project developed procedures and software that can be used to model and analyze software-based control systems for the purpose of verifying and/or assessing its reliability and safety. The use of dynamic, multi-valued-logic system reliability and safety models to support and execute software and system verification and testing tasks represents a significant technical advancement in system safety and reliability analysis. A demonstration of these new techniques and application tools was executed using the Space Shuttle Main Engine (SSME) controller software and system as a test case.

Development of Tools for Safety Analysis of Control Software in Advanced Reactors

U.S. Nuclear Regulatory Commission

This project consisted of an in-depth study of the basic features of embedded system and plant process software, including interactions with the hardware systems that it is intended to control and regulate. The project developed tools to analyze and assure the safety and dependability of software used in digital control and digital embedded systems for nuclear reactors. These tools can identify 1) paths through which certain undesirable postulated events may occur in a system and 2) appropriate testing strategies based on the analyses of system functional behavior.

Advanced methods for modeling team effects on control-room operator performance in real time

U.S. Nuclear Regulatory Commission

The broad technical objective of this research was to develop and demonstrate the use of an integrated model, as well as a set of software tools, that builds on advances in the areas of human reliability analysis, organizational factors, and team dynamics, in order to model and analyze group decision-making processes that take place in a nuclear power plant under both normal and abnormal operating conditions. The resulting methodology complements current Probabilistic Risk Assessment (PRA) methodologies in accounting for team effects and utilizes influence diagrams to model the interactions among the teams. The possible failure modes, e.g., miscommunication between two teams, are modeled by decision tables. Multiple fault trees can, then, be automatically constructed for failures of interest. The associated minimal cut sets provide useful insights into the group dynamics and its possible impact on accident sequences. The results of this project can be applied in reliability assurance, safety assurance and risk assessment tasks concerning the operation of nuclear plants and systems, with specific regard to the effects of the actions of human operators and teams. This work and resulting products is also highly relevant to other industries in which the reliable integration of human operator and teams intervention with system hardware and software is important.

Evaluation of Work Processes at Nuclear Power Plants

Institute of Nuclear Energy Research (INER), Taiwan

This project provided INER personnel with training and documentation on the analysis of nuclear power plant work processes. Work process analysis encompasses the qualitative and quantitative evaluation of the influence of a set of relevant factors on both the design and the implementation of a given work process. It includes provisions for sensitivity analyses for risk-management and resource-allocation purposes. The workshop consisted of a training course and a demonstration/application of the Work Process Analysis Model (WPAM) analytical tool.

Accident Management Advisor System (AMAS)

U.S. Department of Energy

This research developed an Accident Management Advisor System (AMAS) for nuclear power plants. The AMAS concept was demonstrated by developing a logic structure of models and techniques in order to organize existing accident management knowledge bases in a form suited for computer-executable retrieval and inference, and by showing how this structured knowledge base system may be used to assist the accident management activities of plant operators. A suite of engineering workstation software tools, to develop the AMAS inference and decision models and to execute them in real time, was developed using probabilistic logic flowgraph and influence diagram technology. The functionality of the AMAS workstation software was demonstrated on a selection of test cases.