The Multi-Tasking Fallacy

I used to make sweets in a factory for a living.  We obsessed about “set up time”.  The amount of time it takes to switch from one product to another.  Just think about it for a second, every time we switched from making a product with nuts to one without, maybe Snickers to Mars bars we had to:

  • Move out the peanut dispenser
  • Alter the recipes
  • Clean all the peanuts off the line
  • Reset all the cookers and coolers
  • Change over the wrapping machines…

All of this was very visible and time-consuming and as time is money the mantra was two-fold, cut the number of set ups and reduce the time they take to do.  Take out the down time.

There is no set up time in the service industry

Of course we don’t have to worry about that in the service industry.  We employ clever people who can multi-task and better still, with the arrival of the computer age we can present our staff task after task just like that, a call here, web chat there, e-mail next, all with half an eye on twitter, looking for disgruntled customers.

Of course we are kidding ourselves…

A short scientific study

Daniel Weissman at the University of Michigan did a simple multi-tasking study.  He showed people two numbers.  If the numbers were red the subject had to say which number had the largest value.  If the numbers were green they had to say which number was in the largest font.

At the same he scanned his subject’s brains with an MRI scanner so he could literally see what was going on inside their heads.

He found that the brain pauses, then switches between tasks.  It needs time to think.  Red numbers… switch, green numbers… switch, red numbers…switch.  The faster the test, the more prevalent that switching time and the trickier it became.

Set up time doesn’t just apply to factories; it applies to our heads as well.

Who are we trying to kid?

We can’t actually multi-task at all, what we do is focus on one issue, switch, focus on another issue, switch, focus on the third issue, switch…

Switching is easy to do when the tasks use different parts of your brain, e.g. watching the TV whilst cooking the dinner, but if like the sweet manufacturer you are using the same resources to do two different tasks the switching takes a lot longer.  Try holding down a telephone conversation whilst writing an e-mail at the same time and you will know exactly what I mean.

Multi tasking doesn’t make us more efficient, it sucks up time, causes errors and costs money.

What the statistics say

If I haven’t convinced you how about a couple of statistics:

  • 2,600 deaths and 330,000 injuries may be caused in by drivers using mobile phones each year ~ Harvard Centre for Risk Analysis
  • US office workers spend 28% of their time on multi-tasking related transitions and interruptions. (That is $650,000,000,000 a year) ~ Jonathan B. Spira

How do you feel about multi-tasking now?

So what could you learn from manufacturing?

Just like the guys in manufacturing you should apply the same approach:

  1. Reduce the number of changes, let people focus on one task at a time, don’t overwhelm them
  2. Reduce the size of the change, simplify what you do, reduce the complexity of: tasks, rules and regulations.  Don’t make your agents think.

They will be far more productive.

Still not convinced?

Have a look at the diaries of your project managers.  Is it any wonder nothing gets delivered on time?

A last thought for the hard of understanding

How exactly do you feel when your boss is reading his blackberry whilst listening to your presentation?

Can we do two things at once? Well, we’re of the view that we can walk and chew gum at the same time. ~Richard Armitage, deputy secretary of state, discussing the US wars in Iraq Afghanistan and Iraq.

Enjoy this post? Click here for updates delivered straight to your inbox


Read another opinion

Image by ryantron


  1. Well put James.

    My geeky analogy is this; my old desktop computer pretended to multi-task. It would start-off quite happily supporting a spread-sheet and an email client application. I’d then create a presentation document and start copying and pasting data between applications. Then I’d want to retrieve more data from a remote database using a client-side sql query application. As time progressed the computer became overwhelmed as the level of activity it was required to support went beyond what it was capable of. Pop the hood and analysis of computer performance metrics revealed memory pressure causing a significant volume of information to be paged to disk (aggravating an existing disk queue bottleneck), and a high level of CPU processor interrupts (caused by context switching to higher priority tasks). My desktop computer could not really multi-task. The net result was lost productivity as my computer struggled to manage the workload.

  2. Great post. There have been many studies about multi-tasking done but I have not seen the one you linked to before. I like it because it is really about the brain switching and not doing multiple things at once. Your example of talking on the phone and writing an e-mail really drove home the point.

    The studies have carried this over to how many projects a person can handle at once before the law of diminishing returns sets in. All studies I have seen say 2 or 3 projects is the optimum number for one person to handle. I prefer using 2. I have seen it work best when there is one main project to focus on and complete and a second project is used as filler time. An example would be Project 1 is designing a new product. There will be times during the project you need to wait for approvals, testing, samples, etc… During this downtime it is a good time to work on Project 2 that could be something like create a training document or creating a visual board to monitor project progress.

    • James Lawther says:

      Absolutely Matt, yet people insist on pushing for one more job to be taken on board.

      And then they can’t understand why it didn’t get delivered on time.

      Thanks for the comment


  3. James, as I prepare to write that I wholeheartedly agree with your assessment, I must also admit that I’m in the middle of 3 other things, but choose to give this task my full attention (chewing gum notwithstanding). The last time I was debating someone about the whole idea of multi-tasking they had the nerve to put me on hold, come back, and then continue arguing in favor of it. I knew all hope was lost at that point.

    But seriously, I believe many folks brag about multi-tasking as a badge of honor, as if they are the meastro and the rest of humanity the lowly triangle-players. More often than not, though, the more we try to juggle, the bigger clown we become. I did an assessment of my own work habits not too long ago. I noted that I invited in distractions and called it “multi-tasking.” My work area was an open invitation to diversion; there was no indication that anything was central, that one project could rule. I’ve taken steps to fix that, but I still struggle with the ol’ web browser, e-mail and social media bugs. All it takes is one clever blog and I’m off to the races, as you can see.

    Thanks, as always, for an illuminating post.

  4. Hi James,
    Whilst I get it I sometimes wonder if my wife does given that she seems to be supremely adept at talking on the phone and writing an email or playing with a spreadsheet at the same time.

    However, I think you make an interesting observation about project managers. Does the same not apply to ‘programme’ managers and is the problem just compounded?


  5. Jeff Larsen says:

    James –

    Good stuff – My advise would be or better yet Mark Twain’s, “I have never let my schooling interfere with my education.” and of course, chew your gum with your mouth shut.

    My best…Jeff

    • James Lawther says:

      Thanks for your thoughts Jeff, personally I am OK with chewing gum with my moth shut. Just as long as nobody expects me to say anything sensible.


Speak Your Mind