( ) :
(net present value NPV),
(profitability index PI),
(internal rate of return IRR),
(pay-back PB) , .
, , , ( ) .
, . , ,
Rt , t;
It t;
(Rt It) , t - ;
r .
. , ,
t ;
rr .
, . () , ( ) ( ).
:
Dt ;
t ;
rb .
. , . , . , .
, ,
, . , , IRR r (12.5).
, , .