(Demand Forecasting in a Supply Chain):

George has recently joined as a forecasting manager for ABC company and is

interested in developing quarterly forecasts for one of the companys key product.

He has collected quarterly sales data for this product for the past 5 years (2007-2011)

reported below:

Quarter 2007 2008 2009 2010 2011

1 800 1700 2100 2400 3600

2 750 1100 2200 3060 3900

3 600 680 1300 1800 1500

4 1500 2000 3100 4000 3320

George must select the appropriate forecasting method and estimate the likely

forecast error. Which method should he choose and why? Using the method selected,

use Microsoft Excel to forecast the demand for the next three years 2012, 2013 and 2014. Include error measures.

b) Then resolve using Winters Model and compare the results with the previous part. Which method is better and why?