1. A method of implementing a telecommunications feature within a telecommunications switch having memory means and a plurality of system states, said feature being controlled by a feature program which is executed within said memory means, said feature program comprising executable task code, said method comprising the steps of: defining in a first table for said telecommunications feature the various states through which a call can transit and the events which precipitate those state transitions, said first table specifying for a given state and event an index to a list of tasks to be performed in order to complete that transition; defining in a second table an array of lists of tasks, each list specifying a sequence of tasks to be performed in association with that list; defining in a third table for a given state and event an index to the next state to which the call should transition; executing said feature program to access and analyze said first table, via state and event indexes, to determine which list of tasks within said second table is to be accessed; accessing the determined list of tasks and executing each of the tasks on the list in sequence; executing said feature program in response to completion of each of the tasks on said list to access and analyze the third table to access the next state and await the next precipitating event; and modifying the contents of one or more of said tables while said tables are contained within said memory means in order to change the behavior of said telecommunications feature without re-compiling said feature program.