Hon Hai, the Taiwan-based company that runs Foxconn, says the reason iPhone 5s are in short supply is because the device is just plain hard to assemble. One executive at the company spoke directly with the Wall Street Journal about the challenges it has been facing since the iPhone 5 went into production, pointing out that it's taking steps to address scratches and speed up production.
"The iPhone 5 is the most difficult device that Foxconn has ever assembled. To make it light and thin, the design is very complicated," an unnamed Hon Hai official told the WSJ. "It takes time to learn how to make this new device. Practice makes perfect. Our productivity has been improving day by day."
Indeed, an autopsy of the iPhone 5 has revealed that it's jam-packed with parts, with not a millimeter of space to spare. That, combined with issues with scratches on the aluminum surface, has apparently caused a bit of a slowdown in the manufacturing process.