The sentence "the operation was a success" is correct and usable in written English. It can be used when referring to the result of a task or operation. For example: "The heart transplant operation was a success and the patient is now in stable condition."
The operation was a success.
"We believe the operation was a success".
The operation was a success, but the patient almost died.
The operation was a success, but then came the bills.
The operation was a success but the patient died.
The operation was a success, Russian officials crowed.
The surgical team claims the operation was a success.
To judge by Sunday's election, the operation was a success.
The operation was a success, but the marriage wasn't.
The Algerian Communications Minister, Mohamed Said Belaid, claimed the operation was a success.
The operation was a success, and the girl recovered the ability to speak.
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.
Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com