Patent ID: 7239984

Claim:
Method for correcting outlier values in a series of values over time, the values representing a predetermined numerical parameter, the method comprising: for a predetermined time interval of the time series, the time interval having a beginning point (b) and an end point (e), a) calculating an ex-post forecast time series (s_ep) on the basis of the historical lime series (s_h) and a predetermined model function (f); b) defining a lower tolerance limit line (t_min) and an upper tolerance limit line (t_max) on the basis of the ex-post forecast time series and on a quality function (qf) over the time interval; c) beginning at the beginning point (b) of the time interval, correcting the historical time series by replacing the first value of the historical time series (s_h) outside of the tolerance lines by a predetermined value not outside the tolerance lines (t_min, t_max); d) recalculating the ex-post forecast time series (s_ep) on the basis of the corrected historical time series (s_h) and the predetermined model function; and redefining the tolerance lines on the basis of the recalculated ex-post forecast time series (s_ep) and the quality function, whereby the quality function (qf) takes only values into account until the time point where the last outlier value has been replaced; e) repeating c) to e) until all outlier values of the historical time series (s_h) have been replaced; and storing the corrected historical time series is (s_h) for later use by a user.