never change a running system
In real, traceable use. Part of the curated seed collection; community review is coming.
Meaning · English
Do not change something while it is working (because there is a risk of breaking it).
Where it’s used:
Used
American English
Examples
That is, applying a specialised new policy to only improve a temporary capacity extension may be unsuitable (“Never change a running system!”).
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Common questions
What does “never change a running system” mean?
Do not change something while it is working (because there is a risk of breaking it).
Is “never change a running system” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.