Create File Name like servicestart and enter below lines in to that and replace the service=apache2 to anyother service name.
# vi servicestart
if (( $(ps -ef | grep -v grep | grep $service | wc -l) > 0 ))
echo "$service is running!!!"
Save an Close this file.
Put it in to Cron to run at every minute.
# crontab -e
*/1 * * * * /bin/bash /root/servicerestart