Spanish Abstract: Esta monografia describe los riesgos economico y financiero de la empresa (incluido el riesgo de insolvencia y la calificacion crediticia) asi como el los rendimientos economicos y financieros. Se realiza tambien un analisis de dinamica de sistemas de las variables implicadas.English Abstract: This monograph describes the business and financial risk in the firm (default risk and rating included) jointly with business and financial returns. An analysis of system dynamics of the variables were also performed.