The question comes up in almost every demo, and it usually arrives the same way. Someone has built a set with Plan Production, the alignment moved, and they want to know if there is a way to not do the whole thing again. So here is the honest answer first, and then the why, because the why is the part that decides what you do about it.
Native Civil 3D sheets do not update when the design changes. Not in the way people mean when they ask. Plan Production builds a first set quickly, and it is genuinely good at that first set. But each viewport on each sheet captures a window of the model at the moment the sheet is created, and that window does not re-tile itself when the geometry underneath it moves.
What "captured once" actually means
The view frames are the tell. You run the wizard, it places frames along the alignment, and each frame becomes the extent of a viewport on a sheet. That placement happens once, against the design as it stands that day. The frame is a snapshot of a decision: this much of the alignment, at this scale, on this sheet.
When the design holds still, the snapshot stays true and nothing needs doing. A small shift that stays inside the existing frames still reads fine, so you leave it alone, and that is correct. The trouble starts when a change moves the design past where the frames were drawn. The alignment grows at one end. The route shifts enough that the old tiling no longer fits. Now the snapshot and the geometry disagree, and there is no quiet button that reconciles them. You regenerate, and regenerating is where the hours go.
Why the second pass costs more than the first
The first build is a known quantity. You expect to place frames, generate sheets, set up the title blocks, and clean up the seams. It is work, but it is work you planned for.
The second pass is the one nobody budgets. Move the alignment 200 feet at the north end and re-cut the corridor, and the damage runs downstream of the change in a stack. The frames need regenerating. Every match line downstream is now at the wrong station, and the label still points at the old sheet. The viewport behind each one needs re-trimming to the new boundary. If the change added or removed a sheet, the whole set renumbers, and that off-by-one walks through every see sheet label you have, on every tiled drawing, not just the ones along the alignment. The title blocks and the Sheet Set Manager have to be brought back into agreement after that.
I have written about two of these failures in detail, because they are the ones people apologize for most: why match lines drift when the alignment moves, and the renumber nobody asked for when the scope moves instead. Both come back to the same root. The set was built once, for a design that was treated as finished, and the design was never finished.
What "update" should have meant
The fix is not a faster wizard for placing frames. It is sheets that are not placed once.
If a sheet is tied to the geometry it shows, then moving the geometry moves the sheet. The tiling re-seams against the new extent instead of stranding at the old one. The match lines ride to the new seams. The sheet numbers come from one source, so the label, the title block, and the sheet manager cannot drift apart, because there is only one number to read. The viewport behind each seam clips as part of the same operation, so the plan stops at its own boundary without a separate hand-trimming pass.
That is how SheetAgent for Civil 3D treats a set. The first build still happens, and it looks a lot like the work you already know. The difference is the second pass. When the alignment moves, the tool re-tiles the set against the new geometry while the match lines, the labels, the trims, and the numbers come along for the ride. Minutes, not an afternoon. The change goes back to being just a change, instead of the thing that breaks the set.
The honest bound on this
SheetAgent does not read your mind, and it does not pretend the first set builds itself. You still make the layout decisions. What it removes is the tax on changing them. The native workflow charges you the most precisely when the design is least settled, which is exactly when you most want to keep moving. A set that updates with the model lets the design stay fluid without the sheets punishing you for it.
If you have ever moved an alignment and felt the quiet dread of the set you now have to walk top to bottom, that gap is the whole reason this tool exists.
See it on your own project at setline.ai.