Grains are processed into flour and bran during the milling process. The environmental emissions associated with flour are determined by summarizing the total emissions associated with the milling process and subtracting the total emissions associated with the product that the marginal bran displaces in the market. Marginal bran is used for animal feed and is assumed to displace spring barley. Hence, the system of processes involved in analysis of flour is expanded to include the system of processes which are involved in spring barley production and the total emissions associated with flour is determined by subtracting the emissions associated with saved spring barley production from the emissions associated with flour and bran production.

The avoided products are in many cases co-produced with other products, which lead to a whole network of integrated processes and may in some cases result in negative contributions to environmental impacts.