To understand how the interviewees perceived the length of each PD step, we asked what PD step slowed them down the most and what they thought could realistically be accelerated. Most of the interviewees believe that prototyping is the slowest PD step, matching reality. Also, they believe uniformly that prototyping could realistically be made faster. There is less confidence by the interviewees in speeding up any PD activities other than prototyping.