The tendency to think of projects as boxes or separate entities can cause us to miss the material that lurks in the gaps. We may overlook the importance of "both/and" rather than "either/or."
Much confusion resides in the gaps. Who is responsible? How do the boxes fit together? How do and should they "interact?"
Experienced workers almost instinctively know the contents of the gaps. They know both the rules and their exceptions. Unfortunately, such knowledge is frequently regarded as soft.
Training tends to focus far more on box knowledge than on gap and interaction knowledge. Pay more attention to that soft material and watch performance soar.