Words engineers hide behind
fault tolerance
A system that keeps working after one part fails, which sounds like strength and is actually the admission that the part will fail.
Category: Reliability
graceful degradation
Failing slowly enough that someone notices before the customers do. The word graceful is doing a lot of work.
Category: Reliability
redundancy
Buying two of something so that the second one can fail in a way nobody tested. See also single point of failure, which is what you have when the two share a power supply.
Category: Reliability
single point of failure
The component everyone knew about, documented, and did not replace, because replacing it meant a maintenance window.
Category: Reliability
anomaly
An explosion, when the press release is written by the people who built the thing.
Category: Aerospace
off-nominal
Wrong, in a register that implies someone has a procedure for it. The procedure is usually being written as you read this.
Category: Aerospace
rapid unscheduled disassembly
The rocket is in several pieces and the pieces are no longer near each other. Coined as a joke; now used without a smile.
Category: Aerospace
known issue
A bug that has been reported often enough to have a number, and not often enough to have a fix.
Category: Software
won't fix
The bug is real, the fix is possible, and the person who could do it has a different manager.
Category: Software
technical debt
Work that was skipped on purpose, with the interest paid by whoever inherits the code.
Category: Software
deferred maintenance
A bridge inspection that has been rescheduled enough times to become a line item, and then a headline.
Category: Civil
structurally deficient
Not about to fall down, officially. A bridge rating that means one of its main parts scored poorly, which drivers read as about to fall down.
Category: Civil
fatigue
Metal giving up after thousands of small bends, none of which would have hurt it alone. The crack starts where nobody looks: a bolt hole, a weld toe, a scratch.
Category: Materials
stress concentration
A sharp corner, where all the force in a part decides to meet up. Round the corner and the part lasts ten times longer.
Category: Materials
safety factor
How much stronger a thing is than it needs to be, which is another way of saying how little the designer trusts the load estimate.
Category: Design
margin
Safety factor, for people who want it to sound like money. The margin is what gets eaten when the project runs late.
Category: Design
normalisation of deviance
Getting away with something so many times that it stops being a risk and becomes a procedure. The term comes from the Challenger investigation.
Category: Safety
degraded mode
The state every complex system is actually in. Something is always broken; the operators have worked around it so long they forgot it was broken.
Category: Safety
Where this came from
Somebody asked poisonal teach me a little bit about everything
It made 198 things out of that question. This is number 47.
Made 9 October 2026. Written by poisonal ai.
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