1. Planning Demand and Supply in a Supply Chain Forecasting and Aggregate Planning

2. 供應鏈的需求預測 供應鏈決策的階層 界定需求預測的要項 時間數列預測法 估算預測的誤差

3. Learning Objectives Phases of supply chain decisions Identify components of a demand forecast Time series forecasting Estimate forecast error

4. 供應鏈決策的階層 Phases of Supply Chain Decisions 策略性 Strategy or design: 預測 Forecast 計畫性 ( 戰術性 )Planning: 預測 Forecast 作業性 Operation 實際需求 Actual demand

5. Characteristics of forecasts Forecasts are always wrong. Should include expected value and measure of error. Long-term forecasts are less accurate than short-term forecasts: Forecast horizon Aggregate forecasts are more accurate than disaggregate forecasts

6. Forecasting Methods Qualitative Time Series Static Adaptive Causal Simulation

7. Components of an observation Observed demand (O) = Systematic component (S) + Random component (R) Level (current deseasonalized demand) Trend (growth or decline in demand) Seasonality (predictable seasonal fluctuation)

8. Time Series Forecasting Forecast demand for the next four quarters.

9. Time Series Forecasting

10. Forecasting methods Static F t+l =[ L + (t+l)T ] S t+l Adaptive F t+l =[ L t + lT t ] S t+l Moving average Simple exponential smoothing Holt ’ s model (with trend) Winter ’ s model (with trend and seasonality) Excel File

11. Error measures MAD Mean Squared Error (MSE) Mean Absolute Percentage Error (MAPE) Bias Tracking Signal