Scheduling operations

Hi Friends

we had one prodcution orders and 10 operation are there.

First operation 0010 starting on 11.06.11 at 7.00 hrs only operation duration which is 1085 min(18 hrs).

capcity of this operation workcenter is 4.76 hrs break time 1 hr. so when i am claculating it has to finish on (18/4.76=3.78 aprox 4 days) but the sap is showing its tear down on 22.06.11. 7:53 hrs.

How come ?

if i want to complete this on 15.06.11 what i have to do ?

Regards,

srihari.M