reports relating to resource aggregates

[himanshi_garg]

I need to generate a report that shows the FTE availability of all the resources of the organization on a monthly basis. the problem I am facing is that the resources are a part of multiple resource groups, which is making double counting a possibility. 

Can this be done without creating a custom table, if yes, how?

[PaulaaO]

As far as I know it's not best practice to have same resource part of multiple resource groups as it will cause, as you well say, duplication of all aggregates. Leverage Roles (resource_role) and/or Skills if you need a specific resource to be part of more than one bucket, but not Groups. Once you do, the aggregate reporting should be accurate