# Reliability

> [HTML Version](reliability.html)

As default, the bearing life is calculated for a reliability of 90%. The required reliability can be changed here with limits 90% and <100%. The life modification factor for reliability a1 is calculated according to this input using the three parameter Weibull relationship as given as formula in [ISO/TR 1281-2](bibliography.md#iso_tr_1281-2). The table in [ISO 281](bibliography.md#iso_281) is also calculated according to this formula and has changed to previous versions of the standard.