Productivity must be one of the classic goals for people. Whether set as a New Year's resolution or made at some other time of the year, productivity is crucial in all parts of your life. You only have so much time, so to get more in, you must master that resource.

Only, that is harder than it appears. In the Harvard Business Review, two consultants explain why people so often fail at implementing a new productivity system rather than undertaking business as usual. There are three reasons.

Bad habit seduction

Change is hard because it requires breaking old habits and making new ones. We turn back to old behaviors with some rationalization of why it is necessary. The example the authors give is single-tasking versus multi-tasking. The former has been proven time and again to the more effective and efficient in getting things done than the latter. Even one of the most famous time management tips of all times -- one that Bethlehem Steel CEO Charles Schwab valued at what today would be worth more than half a million dollars -- is based on single tasking. Get the most important thing done, then the next most important task, and so on.

But people are sure that their old ways of doing things are better and even necessary. Multi-tasking makes you feel like you're getting more done, even though you aren't. You might even assume that if you don't jump from one thing to another, taking time to check your email or make that "urgent" call, you could get into trouble, even if that is clearly not the case.

To make a new productivity system work, you need to give it a chance and also do some measurement. First create a baseline of how much you got done the old way. Then you can compare and see the new way is actually better, giving you reinforcement for staying with it.

Hostile environment

Bad habits don't exist in a vacuum. People's actions under the habits create the environment and the environment, in turn, creates the actions and, therefore, the habits. For example, if you have your smartphone, tablet, and computer all running at the same time, you might find yourself going from one to the other rather than concentrating on a given task. If your kids are running around constantly trying to get your attention, focus will be difficult to achieve. (If that isn't an understatement, I don't know what would be.)

You need a supportive and consistent environment to practice your new path to productivity. This gets tougher if you don't have sufficient control over the environment. The authors suggest looking for points in your day and routine that are relatively consistent and use them to help set the more productive habits you want to adopt. For example, take the first 30 minutes at work with your own to-do list based on what you, not someone else, want to accomplish and prioritized by date. That way you can make regular progress.

Stress

Stress can interrupt one of the greatest productivity tools we have: habit. Routine activities become automated for the brain because it doesn't need to make any decisions. You just sail in, get things done, and you're on to the next routine. Stress and outside events can make your brain assume that you're in a novel situation, causing you to think too much and disrupting the routine you want to keep.

Thinking too much turns into second guessing yourself, like considering whether the new productivity habits that are working for you are a problem. But this is exactly the time when you need to rely on the new productivity approach. Something you can do is to apply some information from neuroscience and recognize the important decision points, take more effective action during them, and manage your own mental energy.