Hi, Since July I understand that there may have been an update to Proc lifetest which changes the upper confidence interval. I believe this may have been update on our system a couple of weeks ago.   http://support.sas.com/kb/64/617.html   So instead of getting an upper CI my CI is now "NE"    This is the data going into the procedure is below        proc lifetest data=in;     time pfsm*Cnsr(1) ;     run;   Old version CI (1.9,8.1) new version CI (NE)   Point estimate is 8.11499 I'm not a Statistician so can anyone confirm that the new update is correct ? also is there a way to reproduce the old value?   Thanks   Stephen     ... View more