If you're interested in Queuing theory and systems then this book will help. The link only discusses trivial definitions, nothing special. The book is by Prof. Mor Harchol-Balter of CMU. I referred this book extensively during my master's and it is still my favorite academic book. I can open it any day and start reading. The writing is very good. give it try if you're interested. https://www.cs.cmu.edu/~harchol/PerformanceModeling/book.htm...