Use service status command or else make use of below script to check is service is running or not.

Script:

Location: /home/user1/test.sh

#!/bin/sh
service=httpd
if (( $(ps -ef | grep -v grep | grep $service | wc -l) > 0 ))
then
echo "Service is running successfully" 
else
/etc/init.d/$service start
echo "Service had stopped and now its started"
fi

Once you run this script, it will check for the httpd service. You can also place it in cron as follows.

# crontab -e
* * * * * /bin/sh /home/user1/test.sh

Edit the cron as required.