It's the time of year on which we look to hang lifestyle improvements.

But equally important is professional effectiveness, and that's the reason we're taking a look at Peter Drucker's classic.

In some ways, The Effective Executive is now an aging book.

First published in 1967, it covers an era when the executive could only be reached by post or phone, both of which would be screened by an effective secretary.

But the lack of comment on email, text, Skype, Twitter, Facebook et al, doesn't take anything away from Drucker's key message.

All about time

Simply put this is that the majority of the executive's (or indeed the knowledge worker's) time is controlled by the demands of others.

Hence, the ineffective executive (or worker) will always find themselves being overworked.

"Effective executives know that time is the limiting factor," Drucker writes.

And "The supply of time is totally inelastic", adding, for emphasis, "Time is totally irreplaceable".

His point is that the effective executive needs to know how much 'free' time they have available, and ensure that this time is spent on the key projects that will benefit overall company performance.

If they don't have enough free time, then they need to consider what they are doing and make changes.

Time well spent

The starting point for this is to know how your time is being spent. Drucker says everyone should regularly record this on a daily basis over the period of a month. 

This is the starting point to define what current tasks are a waste of time and need to be rejected, or perhaps passed onto someone else.

Of course, an equally valid point for members of the management team to realise in this context is that they often waste their subordinates' time, most notably in pointless meetings. Eight people in an hour-long meeting is eight hours or an entire company work day lost.

For, the conclusion of this short 150-page book focuses less on time per se than what the effective executive is - that is someone who isn't rushed by day-to-day activities but takes the time to make the key decisions or perform the key tasks that improve overall company productivity and profitability.

In the era of email, texts, Skype, Twitter, Facebook et al, it is a lesson that's become more vital for each of us to learn and apply.

You can check out other books recommended in our Reading List here.