Reliability tools have been applied to slope stability analysis more than
any other geotechnical application on account of the readily understood oncept of  “probability of failure” as an alternative or complement to the traditional “factor of safety”. Probabilistic slope stability methods in the literature are reviewed. Particular attention is focused on the ability of the methods to correctly model spatially varying soil properties. A benchmark slope is reanalyzed and conclusions reached about their suitability for meaningful and conservative prediction of slope reliabilit.