Robert N Weinstock

US Patent:

6223143, Apr 24, 2001

Filed:

Aug 31, 1998

Appl. No.:

9/143969

Inventors:

Robert M Weinstock - Bethesda MD
Carol S Smidts - Bethesda MD
Ali Mosleh - Columbia MD
Yung-Hsien Chang - Hyattsville MD
Sankaran Swaminathan - College Park MD
Francisco J Groen - College Park MD
Zhibin Tan - Beltsville MD

Assignee:

The United States Government as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

G06N 700

US Classification:

703 17

Abstract:

A quantitative risk assessment system (QRAS) builds a risk model of a system for which risk of failure is being assessed, then analyzes the risk of the system corresponding to the risk model. The QRAS performs sensitivity analysis of the risk model by altering fundamental components and quantifications built into the risk model, then re-analyzes the risk of the system using the modifications. More particularly, the risk model is built by building a hierarchy, creating a mission timeline, quantifying failure modes, and building/editing event sequence diagrams. Multiplicities, dependencies, and redundancies of the system are included in the risk model. For analysis runs, a fixed baseline is first constructed and stored. This baseline contains the lowest level scenarios, preserved in event tree structure. The analysis runs, at any level of the hierarchy and below, access this baseline for risk quantitative computation as well as ranking of particular risks.