| Variable | Description | Factors to consider |
| Third Party Income | This represents any income stream which may result from the procurement which will reduce the unitary charge | 1.108 - 1.109 If there is more than one source these should be aggregated offline before entering a single input into the spreadsheet |
| Flexibility • Scope change year • Probability factor • Level of scope change • Premium flexibility | • The year in which a major scope change is most likely- this should be the same for the PFI and conventional procurement option so the PFI cell updates automatically • The probability factor represents the user's best assessment of the likelihood of change. Again the PFI cell is hard wired to update automatically when the number is entered for the conventional procurement option • The level of the scope change should be entered as a percentage of the initial capital expenditure. Afgain the PFI cell updates automatically • The premium is only applied to the PFI option as this is the charge to enter into a change notice. It is assumed that for the conventional procurement that the work will be competitively tendered | 1.110 - 1.118 |
| Indirect VFM Factors | The Green book requires public bodies to identify both costs and the benefits which arise from public investment and to monetise where possible intangible benefits. These should be entered into the spreadsheet here in NPV terms. | 1.121 - 1.128 |
| Tax | An estimate is made to reflect the additional tax take that accrues to government under the PFI option in line with the Green Book | 1.129 - A.132 |
| Details of how to apply/ calculate this adjustment can be found at www.hm-treasury.gov.uk/greenbook |