Within three years following the signature of the FWC, the  Contracting Authority  may  offer an amendment to procure additional services from the Contractor(s) up to a  maximum of 50 % of the initial  FWC ceiling . If so, the  Contracting Authority  will use the  negotiated procedure under point 11.1.e of Annex 1 to Regulation (EU, Euratom)  2018/1046 of the European Parliament and of the Council of 18 July 2018 on the financial  rules applicable to the general budget of the Union .  These services will consist in the repetition of similar services entrusted to the  contractor(s) and will be awarded under the same conditions of the initial contract and  to the extent needed by the  Contracting Authority  to fulfil the objective of the FWC within  the overall duration of the contract. The additional services will be awarded in case the  existing or new IT systems require additional projects and services, or require to be  adapted to the needs of the EU legislation on chemicals,  ECHA’s mandate and new tasks  as assigned relating to the scope of this FWC.  The FWC resulting from the award of this call for tenders will be concluded for:  Lot 1: at most 72 months  – 6 years (2+2+2) with specific contracts being valid for a  maximum of 6 (six) months after the expiry of the FWC. The details of the initial contract  duration and possible renewals are set out in Article I.3 of the draft Framework Contract.  Lot 2: at most 72 months  – 6 years (2+2+2), plus two (2) optional years with specific  contracts being valid for a maximum of 6 (six) months after the expiry of the FWC. The  details of the initial contract duration and possible renewals are set out in Article I.3 of the  draft Framework Contract.  For all exchanges with the contractor during the implementation of the FWC as well as for  future possible subsequent proceedings for the purposes of EDES (European Union's Early  Detection and Exclusion System) the contracting authority may use an electronic exchange  system meeting the requirements of Article 148 of Regulation (EU, Euratom) 2018/1046 of  the European Parliament and of the Council of 18 July 2018 on the financial rules applicable  to the general budget of the Union. At the request of the  Contracting Authority  the use of  such a system shall become mandatory for the contractor(s) at no additional cost for the  contracting authority. Independently of the above, ECHA is currently setting up a bespoke electronic exchange  system that may be introduced during the foreseen duration of the FWC. Accordingly, this  internally designed solution may be used for all exchanges with recipients, including the  entering into legal commitments (i.e. specific contracts) and any amendments thereto  under the FWC. By submitting an offer for this call for tenders, the contractor agrees to carry out such  electronic exchanges via the system provided by ECHA. Details on the specifications,  access, terms and conditions of use will be provided in advance. No extra costs are foreseen  for the use of the system.  10 1.9 Electronic exchange system: can exchanges under the  contract be automated?  1.8 Duration of the contract: how long do we plan to use the  contract? 