JUNE 2012 IN

The Tradeoff Between Size and Repairability

A new model of the Apple MacBook Pro has drawn criticism for the difficulty of repairing it. Most components are permanently fastened in place, making the most ordinary repairs prohibitively difficult. Memory chips are soldered in place, for example, so that if a memory chip turns out to be defective, the likely solution is to replace the entire computer.

That design approach is not as harsh as it might sound at first, though. The glue-it-in-place philosophy that makes a product hard to repair also makes it less likely to fail. Looking at memory chips again, how often does a memory chip fail anyway? A memory chip failure was the fate of about 1 in 1,000 computers a generation ago, but by now, the rate is closer to 1 in 1 million. That makes the scenario not so important when you are designing a product.

The glued-in-place MacBook Pro is not just more sturdy and reliable. It is also lighter and less expensive to make because of its design approach. Economically, the tradeoff makes sense if there is a balance between lower manufacturing costs and fewer repairs needed.

Repairing a portable computer is a relatively rare occurrence these days anyway. Sometimes a hard disk drive, screen, keyboard, trackpad, or antenna must be replaced, and these parts are still replaceable in the new MacBook Pro, but beyond this, repairs are the rare exception. It is not that portable computers do not break down, but when they do, it is usually something that cannot be repaired for less than the cost of a replacement computer. And so ease of repair is really not as important as designing the product to not need repair in the first place.

As devices get smaller, they are inherently harder to repair. Shrinking a product eventually means it cannot be held together with screws anymore, but something smaller, usually some form of glue, is needed instead. Yet the cost of making small products is ultimately less than that of large products — the same way that a car costs less to make than a pickup truck — so device sizes will continue to shrink. We will have more and more products that cannot easily be repaired, at least not by a human technician, and that means the products will have to be designed to not break down often.


Afterword: At the end of this month I had the opportunity to repair a Mac mini, which is a desktop computer shrunk to fit into a 16-centimeter square, making it almost as compact as a portable computer. I was doing only the most routine of component replacements, replacing a failed hard disk drive along with two memory modules, but it was not easy. The Mac mini is held together with screws that are almost too small to be accurately positioned with human fingers and a hand-held screwdriver. In the end, on reassembly, I had to leave out two of the six screws. One was rendered useless, as it screwed into a welded plastic post that broke off during the reassembly. Positioning the other was simply beyond the limits of my manual dexterity — and remember, I have the nimble fingers of a lead guitarist.

The Mac mini could have been, and surely should have been, made without those particular screws. That issue aside, though, it is clear to see that the Mac mini, at 16 centimeters across, is already approaching the size limits of repairability. If devices much tighter than this must be repaired, it is work that should be assigned to a robot rather than a person — and the compatibility with the repair robot will have to be built into the original design. In practical terms, though, it will cost less to replace most small devices than to repair them.

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