JESD22-A115C is the machine model member of the JEDEC family of electrostatic discharge sensitivity methods, and its position in that family explains how it was used. The JESD22 methods are selected individually by a reliability or qualification programme rather than adopted as a whole, so a semiconductor supplier would normally report a human body model classification, a machine model classification and a latch-up result together, each obtained to a different method of the same family, and the customer would specify which were required. The machine model classification was for a long period demanded by customers in Japan and by parts of the consumer electronics industry, where the equivalent circuit of a small capacitance with no series resistance was felt to represent the handling environment more closely than the human body model did. Uncertainty about the reproducibility of the waveform and about the correlation with damage observed in production led JEDEC to discontinue the method, and it should now be treated as historical.