Ferrari must consider reorganising its structure in order to return to the top of F1, according to Pat Symonds, who is currently Williams's technical boss.
The 63-year-old Briton is now considering retirement, but he admitted to Italy's La Gazzetta dello Sport that he was offered a job by Ferrari no fewer than three times.
"The first was in 1996, when Michael Schumacher moved with Ross Brawn from Benetton," he revealed.
"I was a senior engineer at Benetton but I saw the possibility to become a technical director, so I wanted to stay.
"The second offer came from Stefano Domenicali in 2012, and the third was in 2014."
However, he said that Ferrari never felt right for him, and now he believes the so-called 'horizontal' organisation structure at Ferrari is not working.
"Believe me, it doesn't work," said Symonds.
"In recent years, McLaren also introduced a non-pyramid shaped structure, but in Formula 1 you need engineers with strong opinions and experts who are able to make decisions that set the direction.
"Ross Brawn was a prime example of such a man for Ferrari. And Rory Byrne. Sure, Ferrari can be successful again, but they need strong leadership.
"It was a mistake of them to let James Allison go. I don't know what happened internally, but I worked with James for many years and have a lot of respect for him.
"He's a great engineer and someone who can inspire his team. I think a Ferrari with Allison would be a stronger Ferrari."
The 2017 calendar gets underway in March with the Australian Grand Prix.
