At the end of last season Andrew, then director of rugby at Newcastle, declared he was not interested in the position because he had unfinished business at Kingston Park.
But the opportunity to head up the England management team and find lasting solutions to the structural problems that have damaged the game proved too attractive to ignore.
"When the process started I was very clear in own mind I wanted to finish the job at Newcastle. I felt I still had lot of work to do," said Andrew, who was English rugby's first professional director of rugby.
"But this job is a massive opportunity to look at the England game going forward.
"It is the most complex structure in world rugby and to understand that structure and try to take it forward is something I changed my mind about doing. I thought it was a once-in-a-lifetime opportunity."
The RFU's chief executive, Francis Baron, believes Andrew's appointment is the best chance English rugby has had to thrash out a long-lasting, workable agreement with the clubs.
Baron said: "For the first time in 15 months we have got positive discussions going with our colleagues in Premier Rugby.
"For Rob to fulfil the potential of his department clearly we need long term solutions to the structural problems that have bedevilled professional rugby since its inception.
"The union is determined to find long term solutions. We must put to an end once and for all to the incessant bickering that has marred rugby in England and put it back.
"There is an opportunity to make a breakthrough and find solutions.
"Rob will play an important role in finding ways to improve the structure of the game so both club and international rugby can thrive."