"I am revisiting a great book – “My Forty Years With Ford” – written by Charles Sorensen. Sorensen was as close to being in charge of production at Ford during the Model T, genesis of the assembly line, $5 day era. The following is an excerpt [...]
'...a part such as a piston entered production bearing a ticket which covered every operation. If ten operations were involved, an entry was made on the ticket after each stage before proceeding to the next one. If one piston was lost in the move, all progress stopped until the missing piece could be found and accounted for. The time consumed in each operation was computed in lots of 100 or more, and results were tabulated on a card file which ultimately found its way back to the foreman so that he might check timing at each stage. Not only did the process mean delay from one operation to another, but when a motor assembler couldn’t get pistons, all car production was held up.'