There's a single harsh reality to be reckoned with when it comes to the number of hours in a day, but countless strategies, tips and acronyms abound for getting the most out of each one. The man who literally wrote the book on "extreme productivity" recently distilled his approach down to about seven steps.

Robert Pozen has had to be efficient to work through the impressive list of responsibilities he's taken on over the course of his career, including stints as an attorney with the U.S. Securities and Exchange Commission, president of Fidelity Investments and executive chairman of MFS Investment Management. His latest book is  "Extreme Productivity: Boost Your Results, Reduce Your Hours," and he lectures at the MIT Sloan School of Management, where he recently shared surprisingly simple tips for going extreme about getting stuff done.

"I see so many people struggling with their daily routine. This is the application of systemized common sense," Pozen explained.

Step 1: Measure productivity in results, not hours.

"Hours aren't a good proxy for what we produce," he said. "I've asked journalists: 'Have you ever spent three weeks on an article that wasn't good? And have you spent three days on one that was really great? What was the more productive use of your time?'"

Step 2: Rank your goals.

Pozen says this one is an important step that few people actually do. How can you figure out how to best spend your precious time if you don't know what your priorities are? When figuring out your rankings, he suggests keeping in mind what you like and what your strengths are, the purpose behind each goal and how they fit into broader overall needs for you or your organization.

Step 3: Break it down if you can.

When faced with small, simple or quick tasks like email, it's better to just get it done right away. If it's something menial that can't just be dealt with quickly, you may need to be a little more strategic, but don't procrastinate, Pozen says:

"Break it into a few easy pieces," he explains. "Start with the easiest one. Once you get started and can do a piece, you'll feel good enough to get on to the next one."

Also, on email, he says to restrict yourself and only check your inbox every few hours, replying to all, but only, those that warrant an immediate response.

Step 4: Start at the end.

An interesting strategy Pozen advocates for more involved and important projects is to begin with what you think will be your conclusions. In part because you can always review and revise them along the way.

"Most people spend six or seven weeks gathering data, speaking to people, and then in the last week or two they spend time trying to synthesize and come up with the key answers. That's an inefficient way to handle research projects," he said. "If you wait, you will gather lots and lots of data that turned out to be irrelevant."

Step 5: Plan downtime for reflection.

Someone once said something about a life without contemplation hardly being worth living. If you must schedule every minute of your day, then schedule in some unscheduled time.

"You need downtime to think--it's part of most people's jobs," Pozen said. This way you ensure your day is aligned with your goals instead of spent in meetings."

Step 6: Minimize daily choices.

This one is tough for me because variety in life and making those daily choices about what to eat and wear can be a small delight.  But Pozen says that the morning, in particular, can be a good time to instead "try to be a boring person" by limiting your options when it comes to what to eat and wear.

Step 7: Don't take it home.

This is another that will be hard for many of us, but is perhaps the most important step, because despite how it often may seem, life is not a game you win by being the most productive and working the longest hours.

"There's rarely a reason to stay at work beyond dinnertime. Get home at a reasonable hour and have dinner with your family. Unplug electronics. Don't take phone calls or emails," Pozen says. "Stop at the door and go through your emails, so by the time you're at dinner, you can focus [on your family] for two or three hours."

Looking back years later, it's likely you'll see those two or three hours each evening as the ones best spent.