Compare each product against its own operating conditions
Suppose a machine produces a short-cycle part in the morning and a longer-cycle part in the afternoon. This illustrative change can lower the afternoon count without indicating a performance loss. Product and expected cycle time are needed to interpret the result.
Keep each job in its own production run and record setup or tool-change time with the appropriate reason. The shift lead can then investigate whether a plan variance came from processing time, preparation or material waiting.