The document outlines a simple cash flow model for calculating free cash flow based on sales and five value drivers: sales, sales growth, incremental fixed capital investments, incremental working capital investments, and operating profit margin. An example is provided to demonstrate how to calculate free cash flow for a company called XYZ using its sales of 10,000 euros and assumptions for the other value drivers. The free cash flow is calculated as 600 euros based on the given inputs and formula.