Forecast Errors
Mean Percentage Error (MPE)
Average of % errors. Shows Bias in % form
Mean Error (ME)
Average of the error terms. Good measure of bias but not accuracy. Negative answer means tendency to over estimate
Thiel's U-Statistic
Compares the forecast technique used to the naive forecast error. The smaller the U the better the technique
Weighted Mean Absolute % Error (WMAPE)
MAPE weighted by magnitude of demand
Root Mean Squared Error (RMSE)
Square root of MSE. Similar to finding Standard Deviation
Mean Absolute Percentage Error (MAPE)
Shows relative accuracy. The average % a forecast is off. Cant calculate if D is ever zero
Mean Squared Error (MSE)
Square each error term and average them. Similar to finding variance
Mean Absolute Error (MAE)
Taking the absolute value of the error terms and averaging them better shows accuracy