4  Implementation

4.1  The provisions of paragraph 6 of Part 1 (General Provisions) shall apply.

4.2  Where the Medium Value Change:

(a)  is implemented at a Facility before the Services Availability Date, and constitutes additional or varied Works, the procedure set out at clause ♦ (Notification of Services Availability) shall apply to the Works which are the subject of the Medium Value Change at the same time as the relevant Facility is subject to that procedure;

(b)  is implemented at a Facility after the Services Availability Date for that Facility, and constitutes works, the procedure set out and agreed in the Contractor Response for certifying the completion of the Medium Value Change shall apply to determine whether the Medium Value Change has been completed appropriately.

(c)  constitutes additional or varied Services, the Payment Mechanism shall apply to determine whether the Medium Value Change has been properly implemented.