The drawer that binds isn't a drawer problem. The door that sags after six months isn't a hinge problem. The lid that slams open and punches a hole in the wall isn't a stay problem.
They're specification failures. Or sequence failures. Or somebody measured the opening, built the box to it, and ignored the gap requirement for the slide family they selected.
Hardware failure is almost always a thinking failure. The hardware did exactly what hardware does. The maker didn't know what to ask.
Four questions. In order.
What does it need to do?
Not what looks good. Not what you used last time. What does this component need to do, specifically, in this piece, under realistic conditions?
A door needs to open to a defined angle, hold there or close on its own, and stay aligned for the life of the piece. A drawer needs to extend the full specified distance, carry the actual load it will carry, and close without catching. A lid needs to stop at a specific angle — not approximately, not roughly — and hold under load.
Write those requirements down before you order anything. They're inputs.
What family solves it?
Hardware families are sorted by function. Hinges solve rotation with gap control. Slides solve linear extension with load distribution. Catches and closers solve retention. Stays solve angle control under load. Shelf pins solve load support at adjustable positions.
The families don't overlap. A slide doesn't solve a rotation problem. A hinge doesn't solve a linear extension problem. This is not a judgment call. Family follows function, no exceptions.
What's the exact spec?
This is where most people get vague. Don't.
For a hinge: door weight, overlay or inset geometry, opening angle, number of hinges by door height. For a slide: the opening width measured, not assumed — then drawer box width equals opening minus the gap spec for the slide family (16mm total for undermount, 25mm for side-mount), extension type, load rating, soft-close yes or no. For a catch: holding force equals door weight times the ratio of center-of-mass distance to catch distance from the hinge. For a stay: lid weight, lid width, stop angle.
The spec is arithmetic. If you're guessing, you'll be rehanging something.
What's the installation sequence?
Hardware installs in two phases. Phase 1 happens before finishing — boring cup hinge holes, drilling pilots, mortising hinge leaves. This is raw-wood work, with clear layout lines and nothing to damage.
Phase 2 happens after the finish has cured. The sequence within Phase 2 is fixed: fixed structure first, then slides, then drawer boxes, then door hanging and reveal adjustment, then catches, then pulls. Each step depends on the prior step being confirmed. You can't set catch placement until the door hang is dialed. You can't dial the door hang until the carcase is done.
Ignore the sequence and you're measuring twice and swearing more.
Hardware doesn't fix a racked carcase. It doesn't fix a drawer box built to the wrong dimension. It doesn't fix a door cut without clearance for seasonal movement. By the time hardware goes on, the piece needs to be right. Hardware closes the piece. It doesn't correct it.
Know the question before you order. Know the spec before you drill. Know the sequence before you open a finish can.
The piece can be beautiful and not work. Get the hardware right and it works. That's the whole job.