I use a custom view in Patch Manager in order to track systems that have current update failures, are pending reboots or have downloaded patches not yet applied.
This is what it looks like:

I'm looking into a custom report which will automatically and periodically track this down for me.
What kind of report (WSUS / WSUS Analytics, Windows Update) do I need, and what are the correct names for these fields? I've tried a bunch of variations but none provide the same data.