  In this work we analyze the deviations of reversible cycles (for both heat
engines and refrigerators) from the corresponding Carnot cycle operating
between the same extreme temperatures and deviations of irreversible cycles
from its corresponding reversible realization while putting emphasis on the
corresponding losses. The endoreversible models fit in the proposed framework.
Two suitable loss factors, which don't need the explicit calculation of entropy
variations, are introduced. The behavior of these factors and their interplay
allow for a clear and pedagogical visualization of where external and internal
irreversibilities are located and their intensities in terms of the main
variables describing the cycle. The analysis could be used as a starting point
for more advanced studies on modeling and optimization of real devices and
installations.
