Homework Solution Weighted Averages - Exponential Smoothing - Trend Cool-Man Air Conditioners Manual ManualComputer-Based TM MGMT E-5070 Part B
Cool-Man Air Conditioners REQUIREMENT: 1.What effect did the smoothing coefficient have on the forecast for Cool-Man air conditioners? 2.Which smoothing coefficient gives the most accurate forecast?
Cool-Man Air Conditioners YearActual Sales α = 0.30 Forecast Absolute Deviation ? Total ( Σ )372.8
Cool-Man Air Conditioners YearActual Sales α = 0.60 Forecast Absolute Deviation ? Total ( Σ )259.0
Cool-Man Air Conditioners YearActual Sales α = 0.90 Forecast Absolute Deviation ? Total ( Σ )190.5
Cool-Man Air Conditioners MAD α = 0.30 = / 5 = MAD α = 0.60 = / 5 = MAD α = 0.90 = / 5 = Because it has the lowest MAD, the smoothing coefficient α = 0.90 gives the most accurate forecast.
WE SELECT THE “FORECASTING” MODULE
WE WANT TO DEVELOP A NEW PROGRAM FOR MOVING AVERAGES & EXPONENTIAL SMOOTHING, WE SELECT “TIME SERIES ANALYSIS”
THE DATA CREATION SCREEN - Insert the number of past years - We can label those months or years any way we want - We can also insert a title for the problem
“ The Data Table ” Appears We insert the annual sales We can also still change the periods titles, i.e. 1 st Year, 1 st Month, etc. “Naïve Method” is the default method
We first forecast via Exponential smoothing ( a = 0.30 )
The 6 th Year Forecast ( units ) MAD Forecast Error ( units )
We now forecast via Exponential smoothing ( a = 0.60 )
The 6 th Year Forecast ( units ) The MAD Forecast Error ( 51.8 units )
We now forecast via Exponential Smoothing ( a = 0.90 )
The 6 th Year Forecast ( units ) MAD Forecast Error ( 38.1 units )
To forecast via 3-Year Moving Average each period is weighted evenly, ( “1” )
The 6 th Year Forecast ( 555 units ) The MAD Forecast Error ( 67 units )
We now forecast via The Trend Projection Method
The 6 th Year Forecast ( units ) Y = (33.6)(6) = The Regression Line Y = X
Cool-Man Air Conditioners REQUIREMENT: 1.Would you use exponential smoothing with a smoothing coefficient of a = 0.30, a three (3) year moving average, or a trend to predict the sales of Cool-Man air conditioners?
Cool-Man Air Conditioners THREE YEAR MOVING AVERAGE Year Actual Sales Forecast Absolute Deviation ? Total ( Σ )134.0
Cool-Man Air Conditioners TIME SERIES FORECAST Year Actual Sales Forecast Absolute Deviation ? Total ( Σ ) 28.0
Cool-Man Air Conditioners MethodMADCalculations Exponential Smoothing ( a =.30 ) / 5 = Three-Year Moving Average / 2 = 67.0 Regression ( Trend Line ) / 5 = 5.6 Regression ( trend line ) is the preferred method because of its low MAD ( mean absolute deviation )
Homework Solution Weighted Averages - Exponential Smoothing - Trend Cool-Man Air Conditioners Manual ManualComputer-Based TM Part B