Mike Bowler
Mike Bowler


Interruptions can be a significant source of waste. By their nature, interruptions cause a context switch as we lose track of what we had been working on to focus on the interruption. There is a significant cost to that context switch as it takes time and effort away from the task at hand. There is also a real impact on quality as mistakes are far more likely to happen when we’re distracted.

I’m not sure which study Nir is referring to here but I did find one1 from a hospital in Adelaide, Australia that was specifically measuring the reduction in interruptions when wearing the “do not interrupt” vests.

Over 8 weeks and 364.7 hours, 227 nurses were observed administering 4781 medications. At baseline, nurses experienced 57 interruptions/100 administrations, 87.9% were unrelated to the medication task being observed … [this change] showed a significant reduction of 15 non-medication-related interruptions/100 administrations compared with control wards

Interestingly, the nurses in the study largely didn’t want to continue wearing the vests after the study although the implication is that this is because they were hot and uncomfortable to wear. The benefits are clear and the obvious next step would be to find a way to keep those interruptions low without causing discomfort for the staff.

I’ve seen many IT teams do similar things to avoid interruptions. One team picked up an old lamp and hung a sign on it “When this light is on, please leave us alone.” That simple lamp worked remarkably well. When the team was working on something that required their focus, they’d set up near the lamp and turn it on and everyone would leave them alone.

Other teams would put rolling whiteboards at the entrance to their team space with “Please don’t interrupt” messages on it on days that they needed to be focused.

Now that most teams are remote, it’s often even easier. We can put our chat applications in “do not disturb” and set email to do the same.

These things work so long as everyone knows that you aren’t always unavailable. When they know that you’ll be available again in a few hours, they tend to respect your focused time.

It’s important to note that not all interruptions are bad. Occasionally truly important items come up where the cost of context switching is worthwhile. One way to reduce the impact of those interruptions is to work in pairs or in a mob/ensemble. When one member of a pair or mob needs to be pulled away the work can continue in a focused way. Additionally, when the member who was pulled away returns they can often slip back into the previous context more easily with their partner(s).