Measurement data in the formation and aging section are generated against equipment channels and tray slots, not against cell IDs; the completeness of cell history is therefore determined not by measurement accuracy but by the integrity of a join key composed of tray ID + slot position + load event. On an assumed line processing about 4.46 million cells per year, formation time series occupy about 1.04 MB per cell and about 4.63 TB per year, while the join-key record is 186 byte per cell, less than 0.02% of the total. Yet a slot misplacement rate of only 10 ppm per load event contaminates the history of about 268 cells…