Multitasking reduces productivity

If you had four tasks to complete before the end of the day, how would you organise your time to achieve this?  One way would be to divide the time available into quarters and dedicate your efforts to each task for that amount of time before moving onto the next task.  Another approach would be to select the least attractive task and complete this before moving onto the others.

If you had recently read a book on time management, your approach to the four tasks would probably be to rank them in priority order and begin working on the most important.

Only when this task is complete or when you can make no further progress on it, would you consider starting the next most important task on the list.  This approach doesn’t automatically guarantee you will complete all four tasks, but it does mean the most important of the tasks will be addressed.

My personal favourite is to use timeboxing.  Approach everything you do in terms of using blocks of time.  You work intensely on task A for, say, one hour then switch to task B for one hour.  In the above example, you would cycle round all four tasks gradually moving them towards completion.  With this approach, you benefit from the application of the Pareto Principle which states that 80% of your results come from 20% of the effort.

If you cycle round the four tasks on your to-do list, you will relatively quickly reach 80% completion on them all.  In many instances, this is actually good enough – there is no real value in striving for perfection and 100% completion.

If you adopted the prioritising approach, there is a risk you could spend so long completing the first two tasks, you run out of time to make any substantive progress on the last two tasks.  It is not dissimilar to taking an exam when it is better to get every question answered to the 80% point than to have some questions comprehensively answered and others only superficially answered.

All the techniques mentioned above will stop you switching from one task to another too frequently.  Every time you switch from one task to another, your brain has to “park” the current task and recall where it was on the implementation of the next task.  It is this park and recall process that destroys your productivity.

In business, I’ve always tried to adopt the Pareto Principle aiming to progress as many tasks as possible to the 80% complete stage.  In the real world, where you will always have far too much to do than time available to do them, it has always made sense to me to spread your efforts over as many important tasks as possible and progress them to a “good enough” finish.

The biggest issue with all approaches to time management is the disruption caused by interruptions.  Your productivity depends on how you handle the inevitable interruptions.  There will be co-workers wanting to talk to you, emails, telephone calls, meetings and suppliers trying to sell you more “stuff”.

For many small business owners, their whole day can be consumed by these and similar interruptions.  Little or no progress will be made on completing the tasks on their to-do list.

As soon as you allow interruptions to break your flow of work, your productivity plummets.  The overhead of stopping what you are doing, dealing with the interruption and then getting your brain back into the original task is significant.  This stop and resume cycle has to occur for every interruption you accept, so you only need 6 – 8 interruptions per hour to seriously impact your progress.

One of the advantages I found with working in blocks of time was being able to ignore interruptions for a short period.

I have developed a method of working in blocks of time where interruptions are ignored until the end of a block.  I work without interruption for a 45 minute block, then deal with a backlog of interruptions (handling queries, reading emails, returning phone calls) as another block.  I try to restrict this to a 15 minute block, but this isn’t always possible.  Once the “interruption block” is over, I put 100% of my attention towards the next 45 minute “working block”.

This approach wouldn’t suit everyone but it has worked well for me over many years.  It does enable progress to be made on key tasks every day.  This was mainly because the stop and resume cycle which arises with every interruption was limited to one occurrence an hour.  Given there is no possibility of eliminating interruptions completely, dealing with them all in one block of time minimises their impact on your workday.

If you combine a method such as timeboxing with the Pareto Principle, you can progress many tasks to the 80% completion point, what I call the good-enough completion point.  Avoid the temptation to strive for perfection or 100% completion.  Remember that 80% of a task will take you 20% of the time it would take for you to reach the 100% completion point.  If you insist on achieving 100% completion, each task will take about 5 times longer.


  1. Periodically review your productivity by thinking about how you handle interruptions during your work day and how frequently you switch between different high-priority tasks.
  2. Where improvements are required, look to implement a strategy that reduces the impact of interruptions and task-switching.  Discipline yourself to continually improve your time management.
  3. Keep the Pareto Principle in mind especially when you have a large or complex task.  Save yourself large tranches of time by working towards a “good enough” completion rather than fully complete individual tasks to perfection.
Posted in Time Management