Use of Fault Trees for Operations and Systems
Abstract
A fault tree is a type of hazard analysis used to graphically show all the events and conditions that must occur in order for a specific hazardous event to happen. If the probabilities of all the conditioning events are known or can be reasonably approximated, a quantitative value for the hazard can be given. The graphical nature of the fault tree allows the reader to see the events that make up the hazard and concentrate on reducing the probability of major contributors. Fault trees are also especially adept at recognizing single-point failures. Fault trees have been used in the government for a long time. The pioneer of the technique was in the safety analysis of nuclear reactors in the 1960s. Many refinements have been made and the standardization of the symbols and process are firmly entrenched. With the incorporation of computer software, fault trees have become much easier to create, no longer requiring recopying whenever an error is found or an event added. Also, computers have eliminated the arduous process of calculating the probability of the top event by Boolean algebra. Currently, fault trees are being used for both operations (movement of ton containers from CASY to the CTF2) and with systems (XM998 Smoke Grenades) at ERDEC. The graphical presentation of the fault tree makes it effective for presentations and can be easily understood in a short period of time. This is a great improvement over forcing a person to go through pages of documentation to find the hazards. This type of analysis is important when a specific hazard probability is desired. The Army's requirement for safe and arm devices to have a failure rate of less than one in a million requires a quantitative hazard analysis.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1996
- Accession Number
- ADA513829
Entities
People
- J. S. Wright