How to restart a program in ubuntu using cron?

Question

I'd like to restart a program regardless of it already running or not using crontab.

I have this in crontab -e

* * * * * /usr/bin/pkill -f myapp; /home/ubuntu/xyz/bin/res.sh

And in the res.sh

#!/bin/bash

/usr/bin/pkill -f myapp

sleep 10

/home/ubuntu/xyz/bin/myapp & &>/dev/null

The problem is if the program is running, it kills the program. but it fails to start the program again.

I don't want to use any condition as to check if the program is already running and start only if it's not.

EDIT: The program is not a service to use "/etc/init.d/service restart" or "sudo service myapp restart"

Thanks.