It absolutely is written down. The issue is that the results you get from modeling systems using queuing theory are often unintuitive and surprising. On top of that it's hard to account for all the seemingly minor implementation details in a real system.
During my studies we had a course where we built a distributed system and had to model it's performance mathematically. It was really hard to get the model to match the reality and vice-versa. So many details are hidden in a library, framework or network adapter somewhere (e.g buffers or things like packet fragmentation).
We used the book "The Art of Computer Systems Performance Analysis" (R. Jain), but I don't recommend it. At least not the 1st edition which had a frustrating amount of serious, experiment-ruining errata.
During my studies we had a course where we built a distributed system and had to model it's performance mathematically. It was really hard to get the model to match the reality and vice-versa. So many details are hidden in a library, framework or network adapter somewhere (e.g buffers or things like packet fragmentation).
We used the book "The Art of Computer Systems Performance Analysis" (R. Jain), but I don't recommend it. At least not the 1st edition which had a frustrating amount of serious, experiment-ruining errata.