Here’s an interesting tidbit from my Project+ studies. Parkinson’s Law states:
Work expands so as to fill the time available for its completion.
In other words, if you schedule “extra” time for work to be completed it will magically take exactly that long to do. People naturally pad to fill the available time. They might do this by wasting time and resources, or making a simple task overly complex, etc. The law was posited in a humorous essay for the Economist, but it really rings true. Be careful to manage any float time carefully, lest you or others fill it just because it’s there!