Taking the CR1 as an example, the mean
squared error is 0.68. Furthermore, the study
calculated the double control limit for the control
charts of forecast. Because the upper control limit is
1.65 and lower control limit is -1.65 in the study, all
of the forecast errors of CR1 were under the double
control limit, as shown in Table 6. The forecast
errors in other CRs are less than the double control
limit. Thus, the exponential smoothing analysis is
clearly quite accurate.