ESTIMATION OF PR(X-GREATER-THAN) OR PR (X-LESS-THAN-OR-EQUAL-TO-Y)

The paper presents a procedure for the estimation (point & interval) for a reliability model of the form Pr{X>Y} or Pr{X less than or equal to Y} and Gaussian (normal) distributed variables. The procedures are derived from a quantitative approach that allows the user to get sufficient evidence, concerning the product reliability, by testing a small sample but at severe conditions, rather than testing a large sample at the nominal working conditions. Y has known parameters while X is a Gaussian r.v. with an unknown mean and a known coefficient-of-variation. The procedure is practical and cost effective when facing situations such as high test-cost, or severe contractual reliability requirements.