(a) What do you understand by a time series forecasting approach? Describe each of the four factors in this approach, and indicate how they are measured or determined.
(b) The historical demand for a product is as follows:
Month Demand
January 12
February 11
March 15
April 12
May 16
June 15
Stating any assumptions that you make answer the following questions.
(i) Using a weighted moving average with weights of 0.60 for June; 0.30 for May and 0.10 for April, find the July forecast.
(ii) Using a simple three-month moving average, find the July forecast.
(iii) Using simple exponential smoothing with α=0, 2 and a June forecast of 13 find the July forecast.