Block Until Done Tool - How to get Input to run first?

Question

Part of my flow requires that a join be done with an external file (it has previous week's values).  After that join is done, that file will be overwritten with new values (current week).

However I need to make sure that the Input runs first to bring in these values, before the output (overwrite) happens.  I tried using the Block Until Done tool, but it doesn't seem to be working.  The Output tool runs first and overwrites the file before Input tool runs.

How do I correctly set this up?

hike44 · Accepted Answer

I used a work around that solved for my specific use case but may not work for everyone else.

I added a Select tool after my final Join to specify the fields I needed and then did the Output.  This seems to have done the trick for my flow but I can definitely see other scenarios where this might not work and a true Block Until Done solution would be needed.