Automatic action doesn't run in GLPI

we need to set cron.php at every 5 minutes interval like
#crontab -l


# crontab -e
*/5 * * * * /opt/rh/php54/root/usr/bin/php /var/www/html/bh.helpdesk/front/cron.php &> /dev/null
save the file

# crontab -l
*/5 * * * * /opt/rh/php54/root/usr/bin/php /var/www/html/bh.helpdesk/front/cron.php &> /dev/null

that's all