Fit and finish

Lots of people have been talking lately about the innovations Apple is making in manufacturing. The most common topic is how Apple is using its huge cash reserves and purchasing power to, in effect, build manufacturing plants for its suppliers so it can get economies of scale almost immediately. Greg Koening likes to talk about how Apple is tweaking materials and employing formerly exotic machining processes.1 What I find fascinating is how Apple is using technology to combine two manufacturing styles that are usually thought to be contradictory: custom building and mass production.

By “custom building,” I don’t mean having customers choose how much RAM or flash storage their MacBook Pros have. I’m talking about using computer vision to identify which component parts—which are already manufactured to tight tolerances—fit the best and to adjust the flow of components on the assembly line to ensure that they go together in the final product.

I’m pretty sure I first heard of this a couple of years ago in one of those “this is Jony Ive, speaking to you from my white space egg” videos, and I was recently reminded of it by Thomas Brand in this Egg Freckles post, in which he pulls out a quote from Apple on its battery design for the new MacBook:

The battery cells in the new MacBook are not only designed with enormous attention to detail, but are also assembled with extreme precision and care. High-speed cameras first take detailed photos of both the casing and the battery. We use those photos to account for microscopic variations in each enclosure, and carefully place the batteries so that not a single millimeter of space is wasted.

What Apple is doing is analogous to what a cabinetmaker does in building a piece of furniture: sorting through pieces and making small adjustments to account for variations in grain and thickness. Only Apple is doing it for millions of devices every month, taking Eli Whitney’s ideal of interchangeable parts and standing it on its head.

I’m not suggesting Apple invented computer vision or that it’s the first company to use it in mass production. But I think it is unusual for it to be used at Apple’s scale for the purpose of wringing every last bit of tolerance out of its products.


  1. If you haven’t already, go read Greg’s iMore article on the durability of the materials used in the Apple Watch.