Setting Constraints in Excel Solver In the segment, you learnt how to set constraints in the 'Solver Parameters' window. One of the constraints that was used for CAT's solution was that 'FF selection has to be binary'. What was the reason behind setting this constraint? One destination ASEAN country can only have a single FF transferring shipments on a particular day. This constraint was set to make sure multiple FFs are not selected for a specific destination country on a specific day. There were only two options available for the decision: To select an FF or reject it. Thus, the constraint was necessary to highlight that the decision has only two options. Since FF selection was represented with the number '1' and rejection with the number '0', this constraint was necessary so that the 'selection' matrix did not have any value other than '1' and '0