3.17 PPP contracts usually require that proposals to change service requirements, particularly where they involve a different 'bundle' of services, need the agreement of the PPP contractor and of the project's funders. This is to allow them an opportunity to assess whether there would be changes to the original risk profile in such adjustments, and whether there are other commercial considerations involved as a consequence. It is likely to alter their plans for the gathering of cost benchmarks, and may affect their commercial relationship with sub-contractors. Therefore, proposals for change should be considered by the public body with these aspects in mind, and sufficient time (at least 2-4 weeks) needs to be built into the project plan for this process to be completed. It would be expected that some form of funders due diligence may be required - this may focus on calibration impact, financial / technical capacity of incoming subcontractors etc.