the Total Number of Vouchers released and/or emitted (TNVO): this parameter will be introduced only in scenarios where a postponed interchange system is working, i.e. scenario 2 and 3. It has to be noted that as the voucher number increases, the administrative cost also increases due to a high resource effort required by additional activities (e.g. expiration date check, legal controversy management, etc.). The unitary cost for administrative procedures due to voucher management has not been introduced in the model.