You can opt for WorkSpaces Manager to automatically change compute type of WorkSpaces. This is useful if, for example, you had a user running heavy spreadsheets on a Standard WorkSpace and it would benefit them with being upgraded to a Performance WorkSpace.
Set Low and High Processor and Memory values (these are up to you). WorkSpaces Manager will also advise you of recommendations.
WSM will also make recommendations if a WorkSpace is oversized based on the users performance needs.