Critical Success Factors (CSF) are SCT components, or life-cycle phases and activities, with a critical positive or negative impact on system development and maintenance. CSF's illustrate the 80-20 law (20% of the components perform 80% of the work etc.). Positive impact means that the CSFs contribute to successful initial implementation of the system. Negative impact implies delays and problems liable to mushroom into significant delays or even system failure. Negative CSFs are not necessarily also positive CSFs.