Most would wonder about what the processing of pipe pieces and of apples could possibly have in common.
I once showed the National Shipbuilding Research Program publication NSRP-0147, that is, Pipe Piece Family Manufacturing (PPFM), to someone who owned a large apple orchard. Until then all of his apples were picked and stored in an atmosphere- and temperature-controlled facility that was located an appreciable distance away. Of course he paid for the special storage, so much per month per number of bins. When marketing conditions were right, the apples were taken from storage for further processing that included detecting and removing those with blemishes. The culls were then sent to a juice plant.
He noted that during PPFM, pipes of two problem categories, i.e., straight pipe pieces and bent pipe pieces, shared a common workflow for cutting pipes, fitting flanges and welding flanges. He also noted that those that were to remain as straight skipped the bending process and proceeded immediately to surface treatment, coating and marking.
Picking up on the logic, the alert apple grower recognized that his apples at time of harvest were also of two problem categories: unblemished and blemished. They could continue to share a common workflow through picking, he reasoned, but thereafter, blemished apples should skip the costly storage facility.
Thus, he trained his apple pickers to watch for blemished fruit and paid them a bit extra to collect the culls in separate bins. Then the culls went directly from his orchard to the juice plant. He received payment from the juicer much earlier than he would have otherwise and rent for storage was reduced accordingly.
I then explained statistical control techniques to the bright apple grower who soon found an application.
Since only apples of one problem category, unblemished, were being shipped to the atmosphere- and temperature-controlled facility, he reasoned that the bruises on apples detected during post-storage inspection were probably due to road bumps during haulage from his orchard to the storage facility by a contract trucker. Thus, he began to relate bin serial numbers to specific truck shipments and, following post-storage inspection, statistically plotted the percentages of bruised fruit that appeared per truckload.
After a few apple-growing seasons the apple grower had identified what was statistically normal for the traditional route that the trucking firm followed and then experimented by specifying alternate routes and maximum truck speeds. Finally, as a consequence of statistical knowledge, he thereafter routinely specified in haulage contracts both a specific route and maximum truck speed. He reported to me that the reduction in fruit bruised in transit more than justified his statistical-control effort.
Dr. W. Edwards Deming would have applauded.