DRS Entitlement Viewer is installed as a plugin to the vSphere client. It is currently only supported for the HTML5 based vSphere client. Once installed, it gives the hierarchical view of vCenter DRS cluster inventory with entitled CPU and memory resources for each resource pool and VM in the cluster. 

Entitled resources can change with VMs’ resource demand and with the VM’s and resource pool's reservation, limit and shares (RLS) settings. So, customers can get the current entitlements based on the VMs’ current demand and RLS settings of the VMs and resource pools.

DRS Entitlement Viewer also provides 3 different What-If scenarios,
1. Changing RLS settings of a VM and/or resource pool
2. What-If all the VMs’ resource demand is at 100%
3. Both 1 and 2 happen together

Customers can pick one of the 3 scenarios and can get new entitlements without actually changing RLS settings on the cluster. 

Finally, DRS Entitlement Viewer also provides an option to export the new RLS values from a What-If scenario as a vSphere powercli command which customers can execute against their vCenter to apply the new settings.