As continuous manufacturing (CM) becomes more prevalent, the question of lot integrity will become more important.  The company where I work presently has been dealing with this question for at least as many years as I have been here and cannot seem to come to a consensus of an acceptable path forward.  In previous lives at companies that had implemented CM, there was an "assumed" amount of carryover based on theoretical calculations of purge volume from transfer tank to filling head.  This may not have been a full CM process in that bulk was still being manufactured by individual compounded batches.  However, even in a truly full CM process, the addition of new raw materials constitutes a new lot.  How does one identify this lot as distinct from the previous?  And at what point does the new "batch" of materials constitute a new finished product lot at the filler/finished package?