former Manchester United boss Sir Alex Ferguson has outlined eight key principles that underpinned his successful managerial career.

Ferguson, who retired in the summer after winning 49 trophies, revealed the theories behind his management in interviews with the Harvard Business School.

Ferguson's blueprint is published in October's Harvard Business Review, and his eight core beliefs are:

1. Start with the foundation Ferguson:

"From the moment I got to Manchester United, I thought of only one thing: building a football club. I wanted to build right from the bottom."

2. Dare to rebuild your team Ferguson:

"I believe that the cycle of a successful
team lasts maybe four years and then some change is needed. So we tried to visualise the team three or four years ahead and make decisions accordingly. Because I was at United for such a long time, I could afford to plan ahead."

3. Set high standards and hold everyone to them Ferguson:

"Everything we did was about
maintaining the standards we had set as a football club -- this applied to all my team building, my team preparation, motivational talks and tactical talks. I expected even more
from the star players [than the rest]."

4. Never, ever cede control Ferguson:

"I wasn't going to allow anyone to be
stronger than I was. If the day came that the manager of Manchester United was controlled by the players -- if the players decided how the
training should be, what days they should have off, what the discipline should be and what the tactics should be -- then Manchester United would
not be the Manchester United we know. "

5. Match the message to the moment Ferguson:

"No one likes to be criticised. Most
respond to encouragement. At the same time, you need to point out mistakes. You play different roles at different times. Sometimes you
have to be a doctor, or a teacher, or a father."

5. Prepare to win Ferguson:

"Winning is in my nature. There is no
other option for me. I am a risk taker and you can see that in how we played in the late stages of matches. All my teams had perseverance -- they never gave in. It's a fantastic characteristic
to have."

7. Rely on the power of observation Ferguson:

"My presence and ability to supervise
were always there and what you can pick up by watching is incredibly valuable. Sometimes I could even tell that a player was injured when he
thought he was fine."

8. Never stop adapting. Ferguson:

"When I started, there were no agents
and, although games were televised, the media did not elevate players to the level of film stars and constantly look for new stories about them.
Players have led more sheltered lives, so they are much more fragile than players were 25 years ago."

No wonder his achievement as a coach.These can apply in other aspect of life such as running a company.