Engineers spend a surprising amount of time worrying about things that haven't happened.
What if this part breaks?
What if the user installs it backward?
What if it gets dropped?
What if the motor stalls?
What if the battery dies at the worst possible moment?
What if a component is manufactured slightly outside its expected dimensions?
To someone outside product development, this can occasionally seem excessive. Why spend time solving problems that may never occur?
Because by the time they do occur, solving them can become dramatically more expensive.
Designing something that works is only the beginning.
A prototype might perform perfectly ten times in a controlled environment. A commercial product may eventually need to perform correctly thousands (or millions) of times while being manufactured by different people and used under conditions the original engineering team cannot completely control.
That's where engineering becomes less about asking:
"Does it work?"
and more about asking:
"How could it stop working?"
Engineers intentionally search for weaknesses while those weaknesses are still inexpensive to fix.
If a potential failure is discovered during a CAD review, changing it might take an afternoon. If it is discovered after prototypes have been built, it might cost thousands. If it is discovered after tooling has been manufactured, the cost can increase dramatically.
And if customers discover it?
Now you're potentially dealing with returned products, warranty claims, damaged reputations, or, particularly with medical devices, something far more serious.
Here's another uncomfortable reality of product development:
People don't always use products the way engineers expect them to.
They skip instructions. They install things backward. They overtighten fasteners. They press the wrong button. They drop things. They clean products with chemicals that were never intended to touch them.
Good product design accounts for foreseeable misuse wherever reasonably possible. That's why you might see a connector that physically cannot be inserted backward or a mechanism that locks before the user can place it into an unsafe position.
These features can seem obvious once they're part of the finished product.
They weren't always obvious.
Someone had to ask:
"What happens if they do this?"
The Tiny Things Can Become Big Problems
Not every engineering failure begins with some dramatic design flaw.
Sometimes it's a tolerance.
Products are systems, which means one seemingly insignificant problem can affect everything around it. Imagine two components that fit perfectly in CAD. In the real world, neither component will be manufactured at exactly its nominal dimensions every single time.
One arrives slightly larger.
The other arrives slightly smaller.
Usually, everything still works.
But engineers have to ask what happens when both parts arrive at the extreme ends of their allowable tolerances.
Do they still fit?
That scenario may occur only occasionally, but if you're manufacturing 100,000 products, "occasionally" suddenly matters.
Engineers don't obsess over hypothetical problems because they expect everything to fail. They do it because development is usually the cheapest and safest place for failure to happen.
Break the prototype.
Find the weak component.
Discover the tolerance problem.
Let someone use it incorrectly.
Push it beyond its limits.
Then fix what you learn.
Because the best time to discover how your product can fail is before your customer does.
If you have questions about the development process, feel free to reach out for help. We do hundreds of free consults every year to help guide innovators along their path of device development.