System safety analysis: fault trees and FMEA

0:00 Intro

System safety analysis, fault trees and FMEA, for the ASP exam. Every rule and number here is cited to its primary source, on screen. In this lesson, you'll learn to: contrast inductive and deductive analysis, distinguish a fault from a failure, build a tree from top event to gates and cut sets, and apply AND and OR probability math and FMECA severity categories.

0:31 Two approaches

System analysis has two approaches. FMEA is inductive. Fault tree analysis is deductive. " You assume a component fault and trace its effect on the system. Deductive starts with one undesired event and works backward to find its causes.

0:51 Inductive methods

Three inductive tools are worth knowing. A Preliminary Hazard Analysis assesses hazards to personnel. It should be done as early in development as possible. Fault Hazard Analysis suits projects with many organizations. It detects faults that cross organizational interfaces.

1:18 FMECA

FMECA evaluates each failure's impact and ranks it by severity, so corrective action targets high-risk items. The criticality analysis supplements the FMEA. It ranks each failure mode by severity and probability of occurrence. Category I is catastrophic: a failure which may cause death or weapon system loss.

Also in the full lesson

• Definitions
• Building a tree
• Cut sets and path sets
• Gate math
• On the job
• Common exam traps
• Recap quiz

The full transcript is included with every ASP pass. See passes

25 questions, free, no card. You get a readiness score for each ASP domain.