Holistically thinking, what are important checkpoints or test infrastructure needed to check for in hardware designed to last for multiple years?
Think of standard consumer products, automobiles, rocket ships, and more! These are all designed to last for a rated lifetime.
Before diving into the types of tests and how they’re performed, it’s important to define what reliability means in the context of hardware products.
Reliability is the performance against requirements over a period of time. Reliability measurements always have a time factor. IPC-SM-785 defines reliability as the ability of a product to function under given conditions and for a specified period of time without exceeding acceptable failure levels.
Typically when we think of consumer products, they’re designed for a rated lifetime and this is where reliability testing comes into place. Once the product architecture is established, the purpose of reliability testing is to ensure the product performs over the course of the specified period of time.
Let’s take for example a handle on a smart home lock. The design requirement specify that the product is rated for 5 years of use. Assuming you have 3-5 open events per day, you’d end up with:
Total Open Events = Daily Open Events*Days in Year*Numberof Years
From there, you can design testing fixtures to mimic the total number of open events to see if the product will function as time elapses.