Consider the following data. We want to monitor the forecasts.
Period..............Demand............Forecasts ......
1...................260....................-- ......
2...................256....................260 .....
3...................288....................256 ......
4...................281....................288 ......
5...................306....................281
Calculate the UCL and LCL for the appropriate control chart? Calculate the cumulative error, MAD, and tracking signals.
Error of period 2
Error of period 3
Error of period 4
Error of period 5
Overal MSE:
UCL to monitor the magnitude of the errors
LCL to monitor the magnitude of the errors
Are the errors in control? Yes No
Cumulative error up to period 2
Cumulative error up to period 3
Cumulative error up to period 4
Cumulative error up to period 5
MAD up to period 2 MAD up to period 3
MAD up to period 4 MAD up to period 5
Tracking signal of period 2
Tracking signal of period 3
Tracking signal of period 4
Tracking signal of period 5
Based on your tracking signals, are the forecasts biased? Yes No