Interruptions: The Secret Productivity Killer
The effects of interruptions on my old programming team were something that I was acutely aware of, and the knock-on task-switching effects that has on technical disciplines.
Although I’ll speak in general, it’s worth noting that this mostly applies to the technical/programming space and may be less applicable to other industries.
The impact of interruptions on workflow can prove hard to understand, especially at management levels that are one-to-two steps removed from “the coal face”.
It’s easy to walk up to someone in your office, ask a quick question and move on. You’ve got what you need, and you were only interrupting them for 5 minutes, right?
Wrong.
Participants in their study experienced, on average, just over four interruptions per hour
There are two big factors to look at here:
- Task resumption
- Task memory
The study showed that, 40% of the time, the disrupted task was not resumed immediately following the interruption
This means that 4 times per hour, the average worker stops what they’re doing, to do something that isn’t their “core job”. Nearly half of the time, they don’t start again right away. So let’s over-average and say that one of your team stops doing their actual job once an hour, doing something else, and does not immediately resume.
There’s a thought that this is about the complexity, for example:
“It’s too hard to start that again, I would need to do XYZ again first, that’s hard, let’s do something else.”
And it’s easy to use the interruption as an excuse to change direction, for example:
“Well, I’ve stopped now anyway.”
Or perhaps it’s about memory:
“What was I doing again?”, “How did that work?”, or “Where did I get up to?”
When a worker is interrupted, it disrupts a (possibly long and detailed) train of thought, making it difficult to quickly jump back in. If the interruption is long enough, it can even lead to forgetting about the task altogether.
Increasing numbers of interruptions and items to be remembered can wreak havoc with both aspects of prospective memory
Prospective Memory is the super fancy name given to the art of remembering what you have to do, and when.
And quite simply the more interrupted someone is, the less likely they are to remember to do what they had to do. The interruptions themselves take time out of productivity, and the associated memory jumps cause things to simply fall between the memory cracks. We are all remembering more and more information, and as the old joke goes, everything new pushes out something old.
At the end of the day, the best thing you can do is to let people decide to interrupt themselves. Some interruptions are a good thing — a break in Outlook to clear the head, for example — but forced interruptions are killing productivity.
Just because you need a break, or have a question, doesn’t mean that Steve needs a break, or has an immediate answer, or doesn’t have his own questions.
37 Signals (creators of Bootcamp) have a great philosophy here. If it’s really seriously super desperate, then OK go for a wander and have a chat. If an answer sometime in the next hour or so is OK, they go for an instant message or a post in their management software. If it can realistically wait for a few hours, or even tomorrow, send an email.
This “structured interruption pattern” allows their “non-communicators” (developers, designers etc — the people doing the real heavy lifting) to read, process and respond when they’re able to, and focus on solving their current problem.
In my old workplace, we implemented a change where the extensions of our developers don’t ring unless the call isn’t answered within a certain time period. This leaves them uninterrupted, and more productive. And productive developers mean more projects delivered on time.
This article is based on Microsoft’s research “A Diary Study of Task Switching and Interruptions”, which can be read in full here: http://research.microsoft.com/en-us/um/people/horvitz/taskdiary.pdf
