The classic study on this topic that everyone loves to cite is "“Constant, Constant, Multi-tasking Craziness”: Managing Multiple Working Spheres", from 2004, where anthropologists observed 14 workers building software, specifically:
* Four software engineers
* Six analysts (more like a Project Manager)
* Four managers (like an Engineering Lead)
What they found is in a ~nine hour day, the people did between ninety minutes to 4 and a half hours a day doing their 'focused work'. You can imagine that project managers are pushing 90 minutes, and the engineers are closer to 5 hours.
All of this is on top of two hours a day chatting with people across cubical walls.
In reading a bunch of these studies, you find small populations, and a focus on law firms and consulting because their work is significantly more legible.
What they found is in a ~nine hour day, the people did between ninety minutes to 4 and a half hours a day doing their 'focused work'. You can imagine that project managers are pushing 90 minutes, and the engineers are closer to 5 hours.
All of this is on top of two hours a day chatting with people across cubical walls.
In reading a bunch of these studies, you find small populations, and a focus on law firms and consulting because their work is significantly more legible.