Do a Google search for the myth of multitasking and you’ll learn that it’s bad for productivity, bad for mental health, bad for concentration; it’s just bad all round. (If you are not convinced, read the top 5 results from the above search.)
It’s bad because we aren’t really multi-tasking at all, we are switching between tasks, sometimes quickly, but mostly slowly. Each of these switches requires you brain to switch context. It has to (effectively) load up a new programme each time to do the new task.
To work on a problem you need information (context). For a programmer they might be working on an algorithm, and they’ve read a dozen articles on related problems. They have all that information swimming around in their head like soap bubbles. Some information is bouncing off others, some is merging with others, some is sticking to the problem at hand, others are repelled. An interruption literally burst these bubbles, forcing a restart.
Context switching is very expensive for software engineers, but what about for their manager? What about their manager’s manager. Or the CEO?
What I am proposing is that context switching is not equally bad for all workers. It is bad for everyone, but it is worse for types of work that require a lot of context. The more context, the worse the switch.
As you go higher up in a organisation roles become less operational, and more strategic. The less operational the role, the less context is needed for making decision, or at least that is my theory. I base that on have worked at all levels of the organisation myself – from programming, managing a team (as a co-contributor), as a leader of a product team, and as a company director.
This effect creates a secondary problem. Those who dwell at each level of the organisation assume that the cost of a context switch is the same for everyone below them in the org chart. That leads people to interrupt those who report to them, thinking that the interruption isn’t as bad as it actually is.
Now I am not saying anyone says to themselves, “interruptions aren’t that bad for me, so I won’t think twice about interrupting others.” It really just stems from a lack of awareness.
If your direct reports work on something that is complex – maths, coding, or anything creative – then the cost of a context switch will be high, much higher than say, you switching from answering an email to writing a report your boss just asked for. The report though is another matter – reports written off the top of your head, based on things you already know, have a low cost to context switch. Reports that require a lot of research, a lot of ‘tabs open’ in your brain, the cost is much higher.
To summarise, context switches are always bad, but the cost of the context switch varies depending on the type of work. In general, those lower down in the org chart require more context to do particular tasks, so the cost of interruptions will be higher for them.
The takeaway: if you have direct reports, or people in your org doing complex or creative tasks, please think twice before interrupting. Interruptions have a huge negative impact on productivity, and your relationship with those people.
Here is a an exercise for you to try at home. Ask your team, or a colleague, to describe to you what happens when they are deep in thought solving a problem, and they are interrupted. The results may differ from your own experience in ways that surprise you. They will certainly change how you behave in future.
Extra for experts: ask your team to call you out if you interrupt them at bad times. Have a team meeting, and work out a better system for having non-urgent conversations. Yes, this may involve you waiting (is it really that urgent?), but you owe it to your team to protect their time, and their brains from unnecessary (and expensive) context switches.