Given the following fields and values in a sales table: -
Year: 2007
Month: Jan
Product_Subcategory_Name: A
Product_Category: B
Territory_Name: C
Territory_Group: D
Sales: $100,000
Info about the data: It contains similar values from 2007 Jan to 2009 Jun and for each Product Category, Subcategory, Territory name and territory group the sales info is given.
How do I use time series forecasting to forecast the sales for 12 periods into the future for each combination of the 4 fields: Product_Subcategory_Name, Product_Category, Territory_Name and Territory_Group? Do I have to calculate the total sum for each field separately and then do the forecasting?