Systems analysis has been applied to hepatology with the aim of providing a reasonable organisation of domain knowledge and supporting the improvement of clinical performance. To this extent liver structures and functions have been classified and defined, clinical parameters have been carefully selected and suitably associated to describe individual liver functions, and methodological criteria for clinical evaluation have been assessed. Three major outcomes of such an approach, respectively concerning the development of a shareable clinical database, the application of a suitable methodology for clinical reasoning, and the computer-based support to medical decision-making, have been discussed.