Step1 Determine Seasonality Pattern Step 2 Compute Seasonality Index - Avg.Season demand/Avg. Total Demand Step 3 For all the time periods - Deseasonalize the data = Demand in t / SI Step4 For all the time periods - Apply exponential smoothing to deseasonalize demand Step5 Compute average forecst as the smoothed value for the last period Step6 Reseasonalize the data - Forecast for s>t = Smoothed forecast for last period * SI Forecast for next season = Use the last value in the deseasonalized smoothed exponential forecast * SI

GoPro is a training camp that help atheletes applying for college improve their sports Most colleges have their application deadline at the end of Decemeber, so the third and fourth quarters tend to be the busiest for the company. Based on the the last three years, management has collected a set of old demand data for various quarters Using a smoothing parameter of 0.2 and an initial forecast for the sesasonalized demand of 130 forecast demand for the first four quarters in 2015

Next period Forecast = * Current Demand + (1-)*Last Period Forecast Year Quarter Demand 2012 1 111 2 120 3 350 4 333 2013 1 130 2 109 3 299 4 305 2014 1 143 2 122 3 401 4 307