About eight or nine years ago, when I ran the global health committee for the oil industry my committee of senior oil co physicians asked me to coordinate a best practices manual on fatigue. We turned (don't laugh) to the airline industry as we assumed that they would have this sorted.
I quickly identified a leading consultant and it was clear that the issues and best practices were well understood. The only thing that surprised me was that there were relatively few airlines on their — or their competitors —books. And the ones that were were not the ones that I had expected — it included an up and coming lo-co for example.
The problem is not the science or the research. It is mostly well known and understood. It is where operators choose to place themselves on the continuum / slider between basic regulation-good practice-best practice.
And, from my observation, the degree to which management pilots are able to stand up to internal forces to cut costs and increase short term "efficiency".