I'm sketching a comparison between manual packing and a future palletising cell. Where do you put the time spent dealing with leftovers from the outgoing product: the old job, the new job, or a separate changeover line?
I can make either job look better by moving that line. I'd rather settle the convention before collecting times. This is about planning, not choosing a robot speed.
Use a separate changeover line, with explicit start and finish events. Keep the whole comparison window as well. Moving a line between jobs should not change its total.
I'd also keep labour time separate from elapsed time, because two people clearing and preparing in parallel shouldn't magically turn ten minutes on the clock into twenty minutes of downtime.
Thanks, the separate labour total is the bit I hadn't allowed for. I'll keep the changeover visible rather than hide it under either product. Still need to define when the outgoing job actually ends.