Learn how a running total of parcels delivered differs from a rate in parcels...

https://www.bust-bookmark.win/running-totals-and-rates-of-change-answer-different-questions-how-much-has

Learn how a running total of parcels delivered differs from a rate in parcels per hour. With clear time windows, this article shows when to ask “how many so far?” and when to ask “how fast?”—so a shift chart is easier to read without mixing units.