Abstract. Knowledge based systems improve information interoperability, integration, and knowledge management. Consequently, there is envisioned a set of the associated business benefits. However, knowledge technology as any other information technology is barely an enabler for productivity and resulting benefits, whereas the real drivers are process optimisation and organisational changes. The paper proposes a valuation method to qualitatively assess organisational and technological capabilities. The business value of system implementation is calculated by accounting for uncertainties explicitly defined in implementation scenarios. The valuation method is aligned to a generic process of system and organisational change implementation.