Service contract conditions of December 2018  Contract number: ECHA/2020/724  Restricted  In the case of machine-to-machine connection, a direct connection is established between the  parties’  back offices . In this case, the parties take the measures necessary on their side to  implement and maintain electronic systems that enable the machine-to-machine connection to  be used effectively. The electronic systems are specified in the  interface control document . The  contractor (or leader in the case of a joint tender) must take the necessary technical measures  to set up a machine-to-machine connection and at its own cost.  If communication via the  supplier portal or via the web services (machine-to-machine  connection) is hindered by factors beyond the control of one party, it must  notify the other  immediately and the parties must take the necessary measures to restore this communication. If it is impossible to restore the communication within two working days, one party must  notify the other that alternative means of communication specified in Article II.5.1 will be used until  the  supplier portal  or the machine-to-machine connection is restored. When a change in the  interface control document  requires adaptations, the contractor (or leader  in the case of a joint tender) has up to six months from receipt of the  notification  to implement  this change. This period can be shortened by mutual agreement of the parties. This period does  not apply to urgent measures required by the security policy of the contracting authority to  ensure integrity, confidentiality and non-repudiation of information and the availability of  e- PRIOR , which must be applied immediately. The parties agree that any e-document, including related attachments exchanged via  e-PRIOR :  The parties expressly waive any rights to contest the validity of such a document solely on the  grounds that communications between the parties occurred through  e-PRIOR or that the  document has been signed through  e-PRIOR . If a direct connection is established between the  parties’  back offices to allow electronic transfer of documents, the parties agree that an e- document, sent as mentioned in the  interface control document , qualifies as an  EDI message . If the e-document is dispatched through the  supplier portal , it is deemed to have been legally  issued or sent when the contractor (or leader in the case of a joint tender) is able to successfully  submit the e-document without any error messages. The generated PDF and XML document for  the e-document are considered as a proof of receipt by the contracting authority. In the event that an e-document is dispatched using a direct connection established between  the parties’  back offices , the e-document is deemed to have been legally issued or sent when its  status is ‘received’ as defined in the  interface control document . When using the  supplier portal , the contractor (or leader in the case of a joint tender) can  download the PDF or XML message for each e-document for one year after submission. After  this period, copies of the e-documents are no longer available for automatic download from the  supplier portal . The contractor submits a request for each person who needs to be assigned the role of ‘user’ in  e-PRIOR . These persons are identified by means of the European Communication Authentication  Service (ECAS) and authorised to access and perform actions in  e-PRIOR  within the permissions  of the user roles that the contracting authority has assigned to them.  User roles enabling these  e-PRIOR  authorised persons to sign legally binding documents such as  15  II.5.5 Authorised persons in e-PRIOR  II.5.4 Validity and date of e-documents  (a) is considered as equivalent to a paper document; (b) is deemed to be the original of the document;  (c) is legally binding on the parties once an  e-PRIOR  authorised person has performed the  ‘sign’ action in  e-PRIOR  and has full legal effect; and  (d) constitutes evidence of the information contained in it and is admissible as evidence in  judicial proceedings.