  In the constantly evolving world of software development, switching back and
forth between tasks has become the norm. While task switching often allows
developers to perform tasks effectively and may increase creativity via the
flexible pathway, there are also consequences to frequent task-switching. For
high-momentum tasks like software development, "flow", the highly productive
state of concentration, is paramount. Each switch distracts the developers'
flow, requiring them to switch mental state and an additional immersion period
to get back into the flow. However, the wasted time due to time fragmentation
caused by task switching is largely invisible and unnoticed by developers and
managers. We conducted a survey with 141 software developers to investigate
their perceptions of differences between task switching and task interruption
and to explore whether they perceive task switchings as disruptive as
interruptions. We found that practitioners perceive considerable similarities
between the disruptiveness of task switching (either planned or unplanned) and
random interruptions. The high level of cognitive cost and low performance are
the main consequences of task switching articulated by our respondents. Our
findings broaden the understanding of flow change among software practitioners
in terms of the characteristics and categories of disruptive switches as well
as the consequences of interruptions caused by daily stand-up meetings.
