A condense study was done for Some times -pool estimator of reliability function
of exponential distribution for time concord data. The estimator ( )
~
2 R t is adjusted to
be
( ) {[exp( | )] [exp( | ( ˆ ˆ ] }
~
2 0 R 1 1 2 2 R R t  t  I  nt K n  n  I
We proposed the estimator
( ) {[exp( ˆ (1 ) )] [exp( ( ˆ ˆ ) | ( )] }
~
3 1 0 R 1 0 1 2 0 0 1 2 R R t  tK   K  I  t n r  n r n  n I 
Study and derivative the equation of bias, MSE, size of data, and relative efficiency
for the proposed estimator and compare with similar and classical estimators, and
given some numerical results to show the efficiency of propose estimator