WORKSHEET #9: The Components of Company Share Change
Create a sample of the company's customer relationships from an earlier period, say three years ago. You might choose to use the same sample of current customers that you developed for Step 2 of Worksheet #8: Company Volume Index on the Size/Role Matrix. However, this approach would exclude the sales volumes of customers that you had in the earlier period but lost in a Get Out event. The approach understates your Negative volatility.
Find the total purchases of each sample customer, both today and at the earlier period.
Find each instance of volatility, both positive and negative, in these sample customers over the last three years.