This International Standard provides methods for analysing data from a Weibull distribution using continuous parameters such as time to failure@ cycles to failure@ mechanical stress@ etc. This standard is applicable whenever data on strength parameters@ e.g. times to failure@ cycles@ stress@ etc. are available for a random sample of items operating under test conditions or in-service@ for the purpose of estimating measures of reliability performance of the population from which these items were drawn. This standard is applicable when the data being analysed are independently@ identically distributed. This should either be tested or assumed to be true (see IEC 60300-3-5). In this standard@ numerical methods and graphical methods are described to plot data@ to make a goodness-of-fit test@ to estimate the parameters of the two- or three-parameter Weibull distribution and to plot confidence limits. Guidance is given on how to interpret the plot in terms of risk as a function of time@ failure modes and possible weak population and time to first failure or minimum endurance.