"I will never set a date to retire," he said.
"I tried that some years ago and made a mistake.
"There are several things to consider but when you get to my age, you have to consider your health.
"Obviously, it is something you cannot control but I do feel good.
"At the moment I am enjoying working with some fantastic footballers, so I have no need to retire."
Ferguson has now taken the place of the longest serving manager in the English game since Dario Gradi left Crewe.
"One advantage I have had as a manager is that I have played the game," he outlined.
"When I started as a young manager at the age of 32, that was the most important credential.
"I also prepared to be a manager. I did all my coaching badges and never missed one summer course in 10 years.
"I was committed to the job and once I went into it I maintained the same things I have today.
"I still have the same work ethic and I don't over-complicate the job.
"But there is some luck attached to it too. You have to be lucky to survive in football today."