Finished-goods receipt, line-side replenishment and returns. The line owns the step. The warehouse owns the bin. Agree codes and posting time before mapping fields.
Finished goods enter the warehouse from a work order. The line asks for components. Defects or leftovers return to a status the WMS understands. Those are documents, not a shared spreadsheet.
MES can say "order 12 is done". It should not silently create bins. Location master data stays in WMS so pickers and later robots share one map.
WMS should not pretend to be the routing. If the pain is shop-floor reporting or quality loops, draw the MES boundary before you write warehouse screens that hide a second MES.
Item, lot, order and "when does stock become available" must be written down. Mapping columns without those nouns is how plants dual-post and then argue all month.
If the aisle is already chaos and the line is still paper, you can stabilize warehouse execution first. If the line cannot say when a unit is done, MES may be the first conversation.
Yes, but estimate them as two object models. A single "factory system" quote usually hides which side is unfinished.
Treat it as the planning or order owner you already have. WMS still owns bins. We integrate; we do not casually replace it.
Write the three documents you already exchange on paper. That is the integration brief.