Once a part has been designed and the operations added, you can release it to the Production tab.
From there, click on "Track Production" in any Work Order to bring up the production tracking box.
In the popup, you can record Setup and Production time, and mark an operation as completed:
Here's a tip: you can open the box to record setup or production time, close it out, and come back later to finish work on the part. Tumult can record multiple periods of setup or production on a single operation.