1.36 Prior to drawing any conclusions from the quantitative VfM analysis, Procuring Authorities should take account of the sensitivity of the indicative PFI VfM value to changes in key input variables. Equally, they should bear in mind that the Indifference Point analysis tests the sensitivity of VfM to changes that affect either one or other of the procurement methods but not both at the same time. This will be particularly important where there is significant uncertainty around the validity of certain inputs. Where there is a high level of uncertainty around inputs, or outputs are highly sensitive to the input variables, it is appropriate to accord greater weight to the qualitative assessment or to invest more time and money in establishing higher confidence in the most critical assumptions. Procuring authorities should in any event undertake appropriate sensitivity analysis.
1.37 Sponsoring Departments should work to assist Procuring Authorities by establishing certain benchmark tolerances for Indifference Points which, if relatively easily breached, might suggest that further analytical support should be provided to the Indicative PFI VfM value determined by the Spreadsheet. Table 1.E identifies the default benchmark tolerances for Capital Expenditure and the Unitary Charge that might, in the absence of sector-specific information, be used in this way. The results should then be placed in the context of the qualitative analysis even where they lie significantly outside the given tolerance. The Authority should also ensure that all the underlying assumptions and scenarios are documented as set out in Section 5, Documentation Checklist, of the main guidance.