Excel report is generated each time the task is run if the Synchronize with option is enabled. It builds as comparison report of two database schemas in the form of a protocol of the result synchronization script, even if SQL script itself is not created at the same time.
The report, like the comparison itself, is performed based on the specified settings for comparison and synchronization. Be sure to specify all possible manipulations with those categories of objects for which you want to build a report: create, add, update, rebuild, drop, except for common types of manipulations (Recreate All, Delete duplicates).
To exclude chains of dependent objects from a report, disable the option Rebuild children and hard-dependant objects. But only for a report! In most cases, you can not create a valid synchronization script of database structure without rebuilding the children or dependent objects.