When you build to tight tolerances, the smallest parts carry the biggest risk. One fastener that is out of spec, or simply missing, can bring a whole line to a stop. Keeping C-parts dependable comes down to a few things that are easy to underrate: steady quality you can trace, a replenishment setup that does not let you run out, someone to call when a spec changes, and pulling all those small, low-value items under one supplier instead of a dozen. To see how a managed replenishment setup works day to day, take a look at our guide to vendor-managed inventory.