Software upgrade  mean any intended change of the Equipment software other than a software  update, for example, to adapt to the presence and use of other hardware items including computer  and its operating system. It must include all necessary labour and onsite visits to demonstrate  satisfactory Equipment performance. Where the usage of consumables and spare parts  necessitates the change of Equipment software such software update shall be deemed a  replacement of the respective item.  A warranty or guarantee as per article I.13 of the contract is an assurance that the manufacturer  makes regarding the condition of its product. It also refers to the terms and situations in which  repairs or exchanges must be made in the event that the product does not function as originally  described or intended. It includes any break down of the equipment that was caused by faulty  design (or similar) and/or is not attributable to the Contracting Authority.  The warranty must include any corrective actions necessary to re-establish proper functioning of  the Equipment. The contractor shall repair and/or replace, free of charge, any component or part of  the result as a whole that is proven to be defective during the warrantee/guarantee period. There are  no limit interventions for the corrective actions during the warranty period.  This warranty period must commence once stage 1b is completed and accepted. Under the  conditions of the contract, this period runs parallel with stage 2 and shall last  twelve (12)  consecutive months . If the spare parts are replaced require periodic calibration/maintenance, the service shall be included  free of charge in the guarantee. Finalisation of the Equipment design and engineering starts after signature of the contract.  Equipment manufacture must start once the Commission based on the final P&ID and part list  included in the final offer during the negotiation.  This stage shall not exceed  twelve (12) consecutive months . Prior to the delivery of the Equipment to the Petten site, it must be subject to a Factory  Acceptance Test (FAT) on the site of the manufacturer that may be withnessed by technical staff  of the Contracting Authority. The FAT must include demonstration of the Equipment on all  functions and capabilities as specified in this technical specification to verify its compliance. The  FAT cannot prejudice the outcome of Equiment commissioning. The contractor must inform the  Contracting Authority at least three weeks in advance on the date of the FAT.  This stage ends on the date of the delivery of the Equipment according to the mandatory  requirements as set out under chapter 3.1 and attested by the signed form contained in Annex IV _  certificate of conformity - of the contract and the release of the FAT report. The payment of this  stage is conditioned by the FAT approved by JRC  10  TS-JRC/PTT/2021/OP/CNP/0763  6. PERFORMANCE OF THE CONTRACT  STAGE 1A: EQUIPMENT ENGINEERING, MANUFACTURE AND FACTORY ACCEPTANCE TEST (FAT)  Warranty 