Is the co- product of interest determining for process A? Can the outputs of the co- product be independently varied? Is the dependent co- product fully utilised? Is the dependent co- product fully utilised? Step 1: Treating combined production                                                  YES Joint production:           NO Step 2: Identifying determinant for   process A                               YES                NO Step 3: Identifying determinant for   intermediate process                YES                 YES                 NO                          NO            Step 4: Identifying displaced processes (D or W) when relevant Figure 5.3. Decision tree showing the 4-step procedure for handling co-products. Include the consequences of changing the output of the co-product of interest while keeping other outputs fixed Use rule no. 1+2: Ascribe A and I to the co-product of interest and credit it for process D Use rule no. 1+3: Ascribe process I to the co-product of interest and credit it for avoided waste treatment (W) Use rule no. 1+3: Ascribe the co-producing process (A) and the waste treatment (W) to the co- product of interest Use rule no. 1+2: Do not ascribe any part of A or I but use supply from process D