text: **II.5.3. Submission of e-documents via e-PRIOR**
  
  1. If provided for in the special conditions, the exchange of electronic documents (e- 
  documents) such as requests for services, specific contracts and invoices between 
  the parties is automated through the use of the*e-PRIOR*platform. This platform 
  provides two possibilities for such exchanges: either through web services 
  (machine-to-machine connection) or through a web application (the*supplier*
  *portal*). 
  
  2. The contracting authority takes the necessary measures to implement and maintain 
  
  electronic systems that enable the*supplier portal*to be used effectively. 
  
  3. 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. 
  
  4. 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. 
  
  5. 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. 