1. A method of generating a forecast system using a forecast system development tool, the method comprising: selecting one or more generically structured core forecast algorithm components, each providing a non-optional function for a forecast heuristic component; and optionally, selecting one or more optional forecast algorithm components, each component providing an optional function for said forecasting heuristic algorithm, the method further comprising the steps of: associating each selected component with a framework whose structure determines the relationship between said component, associating each selected component with a set of one or more rules provided by said forecast heuristic component, whereby each forecast algorithm component provides an algorithm which is individually tuned in a predetermined sequence determined by said framework, the first forecast algorithm component in said sequence performing a tuning process on said set of time-series data and wherein subsequent forecast algorithm components are tuned using time-series data conditioned by all of the tuning processes previously performed in said predetermined sequence, whereby collectively, the sequence of forecast algorithm components determined by the framework and said heuristic forecast component forms said forecast system.