A more accurate name for this method of working is switch tasking, and it is an inefficient and inadequate way of getting things done.
There are plenty of studies to back this up, including a recent one from Vanderbilt University. Researchers couldn’t find a single piece of neurological evidence to suggest that the human brain can take on more than one task at a time.
What the brain can do is switch back and forth, from one task to another. It can do this quickly enough to give you the impression that it is multitasking, but what it is really doing is switchtasking.
Switching between tasks is ultimately inefficient and a waste of time, because whether you are making active or passive switches, you will inevitably need to stop one train of thought to start another.
Avoid interruptions by making yourself available to employees and coworkers at regularly scheduled times.