ABC Corporation has given you the following information sales history.
Quarter Demand ____________ 2012 2013 2016
1 10 12 17
2 20 25 32
3 15 17 19
4 9 10 15
a) Plot the quarterly sales data for each year
b) What are the trend and the seasonal index for each quarter?
c) Assume exponential, trend and seasonal smoothing with α = 0.2, β = 0.3 and γ = 0.4. Forecast the demand for the 2nd and 3rd quarter of 2017.
If actual demand during the 1 quarter of 2017 is 50, find the updated seasonality index, level and trend for 1 quarter 2017 and forecast the second quarter of 2017.