Back in the 1990s I was fortunate enough to work for a very smart, energetic man. In a way, working for him, or at least in the position he gave me, changed the trajectory of my career.
Skipping 99% of that story ... one thing he did exceptionally well was troubleshoot problems, and troubleshoot them very fast. I didn’t know it at the time, but he was using something called The Scientific Method. After observing him for a while, I saw him repeat these steps so precisely that I thought he must have them on a tattoo on the inside of his eyelids: