At the boundary between equipment (ISA-95 Level 2) and MES (Level 3), the main reason traceability events erode takt time is not the transport method (polling vs. subscription) but a structure in which the MES acknowledgement (handshake) sits serially on the critical path of the station cycle. On an 8 GWh/year cell line (assumed takt time 3.14 s, net station processing 2.80 s), 1.0 s polling with a synchronous handshake adds an average of 0.72 s, stretching the cycle to 3.52 s and creating a shortfall of about 10.9% against required quantity; switching to a 0.1 s/0.2 s subscription still adds 0.37 s on average and still exceeds takt time.…