Demand for Varsity Letterman jackets at Teens Forever for the last 12 months is as follows:

a) Estimate demand for the next three using a 3-month moving average, simple exponential smoothing with a = 0.1, and Holt’s model to estimate the demand with a = 0.1 and fl = 0.2.

b) Evaluate the MAD, MAPE, bias, and TS (i.e., the KPIs) in each case. Which of the three methods is better? Why?

c) What should the values of a and in Holt’s model be in order to minimize the MAD?