Jean-Louis Gassée does the math.
From Gassée’s Monday Note, Apple Culture After Ten Years of iPhone:
It’s difficult to build a live mental picture around numbers this large. In our minds, we can easily move the pieces on an imagined chessboard, or assemble and reassemble the seating arrangement for a Thanksgiving dinner, but how do we picture a trillion dollars or a billion phones?
Let’s see if we can bring these unimaginable quantities into a manipulable picture.
During the most recent Xmas quarter, Apple sold slightly fewer than 80 million iPhones, about 900,000 a day. Obligingly, a day has 86,400 seconds, so we round up to 90,000 to get a production yield of ten iPhones per second.
But producing a phone isn’t instantaneous, it isn’t like the click of the shutter in a high-speed camera. Let’s assume that it takes about 15 minutes (rounded up to 1,000 seconds) to assemble a single iPhone. How many parallel production stations do we need to accumulate ten phones a second? 1,000 divided by 1/10 equals…10,000! Ten thousand parallel stations [“pipes” in Gassée’s latest update] in order to output ten phones per second.
This leaves Gassée, and me, with new admiration for the former COO who assembled this vast supply chain, and for the former CEO who had the foresight to hire him.
See also: Horace Dediu’s The First Trillion Dollars is Always the Hardest