This book explores the application of the second law of thermodynamics to a variety of systems beyond the typical evaluation of thermal machines. It utilizes quality indicators as tools for diagnosing different energy conversion systems, addressing issues ranging from system failures to the rational use of energy in society.

The analysis is divided into two types: the first from the skin to the core of a biological system, and the other from the skin to the environment, known as society exergy analysis. The latter is a new field currently being developed.