Abstract: A forecasting tool and methodology are described for generating a quantitative index indicating the current state of a system. The system may be affected by a plurality of events. A numerical value, based on the current situation, is assigned to each of a plurality of factors identified as influencing the event. The numerical values are used to calculate a likelihood metric for the event occurring. An impact factor value, which indicates the impact that the event occurring would have on the system, is combined with the likelihood, to calculate the quantitative index. Indexes for different forecasting periods can be calculated using numerical values for different periods of time. A forecasting tool and computer program implementing that tool are also described. The forecasting methodology can be used to provide an index which is published or used internally by an organisation. The forecasting methodology can also be used as the basis of a consulting service provided to an organisation.