It appears that serverb.example.com is not available from the tower instance:

[root@tower ~]# ssh serverb.example.com
ssh: Could not resolve hostname serverb.example.com: Name or service not known

Check the status of the environment using ansible:

ansible all -m ping

This command establishes a connection to all the machines in the environment (except ESXi servers). In case the machines are up an running a success message, per each, will show up. This is an example of a success message for the VM jboss0.example.com:

cf.example.com | SUCCESS => {
"changed": false,
"ping": "pong"
}

ansible.cfg config file = /root/RHS-Path_2_HANA/playbooks-for-hana/ansible.cfg is as follows:

[defaults]
inventory=/home/ansible/ansible-files/inventory

The inventory file does not exist in tower.