  In this thesis, we investigate the emergence of kinetic processes in finite
quantum systems. We first generalize the Redfield theory to describe the
dynamics of a small quantum system weakly interacting with an environment of
finite heat capacity. We then study in detail the spin-GORM model, a model made
of a two-level system interacting with a random matrix environment. By doing
this, we verify our new theory and find a critical size of the environment over
which kinetic processes occur. We finally study the emergence of a diffusive
transport process, on a finite tight-binding subsystem interacting with a fast
environment, when the size of subsystem exceeds a critical value.
