At the next mold change on any press, one person with a stopwatch times four parts.
First, the wait for the next mold, hoses and tools.
Second, taking the old mold out and bolting the new one in.
Third, connecting the water hoses.
Fourth, the run from the first shot to the first good part.
Cost
About $68 of one person's time, at $52 per hour.
A supervisor or a second technician watches one whole mold change, then takes a quarter of an hour to write it up.
Nothing is bought, and the change is one that is made anyway.
Duration
One mold change, then a quarter of an hour of notes
Confirmed if
The press waits more than about 8 minutes for the next mold, hoses or tools. From there, the carts pay back within a year by our figures.
Ruled out if
The next mold, hoses and tools are at the press when it stops, and the minutes go to the swap, the water hoses and start-up. A cart then has nothing to save.