Journal or Book Title
Analysis of product lifetime data typically calls for estimating product reliablllty-together with an associated statistical confidence Interval-after a specified lifetime. For product lifetimes that do not exceed the longest time to failure in the given data, such estimates and intervals can be calculated without making any assumption about the statistical lifetime distribution, using so-called "nonparametric" methods.
Doganaksoy, Necip; Hahn, Gerald J.; and Meeker, William Q., "Assess Your Lifetime Model" (2018). Statistics Publications. 328.