What is the technical term for. . .

[slowtiger]

Terms have different meanings everywhere. The word "blocking" I've heard less than ten years ago, I don't really like it.

I do lip sync as the really last step in animation, because I'm oldschool and have learned that you need to express the meaning and emotion with body language first, and dialogue is only secondary. This also stems from the Disney tradition of drawing each head pose, so you can't apply a predefined set of mouth shapes to it. Of course with long sequences of talking heads which don't move otherwise this would be different, but my habit remains.

[chucky]

Layout is a close term; I would have almost said that.
However, layout is one is two steps back from what you might be looking for, which could well be the process ' scene planning', which although may sound like it has nothing to do with the writing.
This is where the assets, like rigged characters and backgrounds are loaded into a file and placed around, according to the layout, by the scene planner (a specific job in many studios working on series).
This happens after the designs. storyboards, layout, rigs and props are all finished, ready for animators to step in and follow the boards with all those correct assets.