Stop SAP does not work

When I executed the command stopsap r3 It did not stop the SAP application.
It did not kill the sapstart and dw work process.

Solution:
In the dir /usr/sap/ND1/DVBMGE17/work kill.sap was there but no entry was there.
Generally it stores the PID of sapstart
Then I did : ps -ef | grep sapstart
get the PID
and add this in kill.sap
echo "kill -2 <PID of sapstart>" > kill.sap
and it successfully stopped.
Actually during stopsap it searches for kill.sap and do the entry in it