Although the Italian outfit kept itself within mathematical contention until the Indian Grand Prix, Domenicali said in the wake of rival Sebastian Vettel's fourth championship that he knew the writing was on the wall weeks ago.
"I think honestly there were two moments when I realised that the situation was becoming quite complicated," explained Domenicali.
"One was around July when we saw that we didn't have the step in performance related to the upgrades that we were hoping to have.
"That was a sign of alarm I saw very clearly.
"The second moment was in the second half of the season.
"If you think about Spa and Monza the situation was not so bad if you forget Sebastian and Red Bull, but we were not able to gain with the change of tyre specification, while we saw the others did a big gain.
"They were the two alarms that I saw during the season. They were the moments when I realised that things were not going in the right direction."
Domenicali accepted that Ferrari has not done a good enough job this season.
"Last year we could have won the title without having the best car," he said.
"But we were good in the other elements you need to make sure that you are a winning team.
"This year I think we were not really good in developing the car and managing the tyres.
"This was a big thing for our performance, no doubt."