Focus time – Does it work with all types of work?

I love the idea of blocking time to focus every day, however, with the work I am doing it is almost impossible to plan as suggested. My job is mainly coordinating between different individuals and I am always dependent on the other parties. Even if I set deadlines, things arrive late or they arrive but in bad quality (or they arrive in an astonishingly good quality 😉 ), which makes it very hard to plan. The major part of my job is (last minute) problem solving and every week turns out to be different than anticipated in the beginning.
Do you have any recommendations for time management in such types of jobs?