This paper presents the use of time series ARIMA model with interventi
ons, and neural network backpropagation model in analyzing the behavio
r of sales in a medium size enterprise located in Santa Maria (RS), Br
azil for the period January 1979 - December 1989. The forecasts obtain
ed using the backpropagation model were found to be more accurate than
those of ARIMA model with interventions.