PPP Model Checklist
Executive Summary
Key Takeaways
- ✓ PPP and concession models carry contract-specific mechanics — availability payment deductions, demand risk sharing, and handback conditions — that must be tested against the underlying concession agreement, not just the model's internal consistency.
- ✓ Availability payment deduction and performance point mechanisms should be tested as live formulas responding to modelled performance failures, not confirmed complete based on a base-case scenario where no deductions occur.
- ✓ Concession life and handback assumptions materially affect terminal value and required reinvestment, and are frequently under-scrutinised relative to construction and operating period assumptions.
- ✓ Government agencies evaluating competing bidder models require the same rigour applied to a single sponsor's model, since inconsistent modelling conventions between bidders can distort a fair comparison.
Objective¶
This checklist verifies the contract-specific mechanics of public-private partnership (PPP) and concession financial models: availability payment calculation, demand-risk allocation, concession-life consistency, and handback conditions. It exists as a distinct checklist because PPP models are built around a specific contractual structure with the public authority that does not appear in a standard project finance or corporate model, and is not covered by the Lender Model Review Checklist, which this checklist assumes has already been applied for the underlying debt mechanics.
PPP models must be tested against the actual project agreement, not just internal consistency, since the value of the model depends entirely on whether it correctly implements the specific payment mechanism, risk allocation, and handback terms the public authority and sponsor have contractually agreed.
Applicability¶
Applicable when a financial model is being built or reviewed to support a public-private partnership, concession, or availability-based infrastructure contract, including toll roads, social infrastructure (schools, hospitals), and availability-payment utility or transport concessions. Relevant to government agencies evaluating bidder models in a tender, sponsors preparing a bid, lenders financing a concession, and advisors conducting an independent review.
Checklist¶
| # | Check Item | Why It Matters | Evidence to Collect |
|---|---|---|---|
| 1 | Availability payment deduction mechanism is modelled as a live formula responding to defined performance failure scenarios | A deduction mechanism only shown passing in the base case has not actually been tested; deductions must be verified to trigger correctly when performance fails | Deduction mechanism stress test results |
| 2 | Availability payment calculation matches the payment mechanism defined in the project agreement exactly, including any indexation | A mismatch between the model's payment formula and the actual contract terms misstates the entire revenue base | Payment mechanism cross-check against project agreement |
| 3 | Demand risk allocation (revenue tied to usage versus availability) is modelled consistently with the actual contractual risk allocation | Blending demand and availability revenue incorrectly misrepresents which party bears usage risk under the contract | Risk allocation cross-check against contract terms |
| 4 | Concession or contract term length matches the project agreement exactly, with no undisclosed extension assumption | An incorrect concession-life assumption misstates the entire cash flow period available for debt repayment and equity return | Concession term cross-check against project agreement |
| 5 | Handback condition costs and any associated reserve are explicitly modelled in the final years of the concession | Omitting handback costs overstates terminal-period cash flow and understates the sponsor's true end-of-term obligation | Handback cost and reserve documentation |
| 6 | Performance points, key performance indicators, or penalty regimes in the contract are each individually represented, not aggregated into a single blended deduction | Aggregating distinct penalty mechanisms into one factor obscures which specific performance failure is driving a deduction | Performance point-to-deduction mapping |
| 7 | Indexation (inflation-linking) of payments matches the index and mechanism specified in the project agreement | Using a generic inflation assumption instead of the contractually specified index misstates long-term revenue | Indexation mechanism cross-check |
| 8 | Change-in-law or force majeure compensation mechanisms, where defined in the contract, are represented or explicitly flagged as excluded | Silent omission of a contractually defined compensation mechanism understates the model's completeness relative to the actual risk allocation | Compensation mechanism documentation or exclusion note |
| 9 | Senior debt DSCR and LLCR are recalculated incorporating the full availability payment and deduction mechanics, not a simplified flat revenue assumption | A simplified flat revenue proxy can materially overstate coverage relative to a fully modelled, deduction-exposed revenue stream | Independent DSCR/LLCR recalculation |
| 10 | Refinancing gain-share mechanisms, where present in the contract, are modelled and allocated between public authority and sponsor per the agreed formula | Omitting or misallocating a refinancing gain-share misstates the economics of a common PPP contractual feature | Refinancing gain-share mechanism check |
| 11 | Where reviewing multiple bidder models for a single tender, modelling conventions (discount rate basis, inflation assumptions, base date) are consistent across all bidders being compared | Inconsistent conventions between bidder models distort a fair like-for-like comparison, independent of each model's individual quality | Cross-bidder convention consistency check |
| 12 | Equity IRR and debt coverage ratios reflect the full concession term including any handback-period cash flow reduction | Truncating the analysis before handback-related costs are incurred overstates the sponsor's actual return | Full-term IRR and coverage recalculation |
Common Failures¶
- Availability payment deduction formulas present in the model but never actually triggered in any tested scenario, leaving the mechanism functionally unverified.
- Concession term modelled inconsistently with the project agreement, often due to an undisclosed extension or renewal assumption carried over from an earlier draft.
- Handback condition costs omitted from the terminal years of the model, overstating the sponsor's realised terminal cash flow.
- Demand risk and availability revenue blended into a single line item, obscuring the actual contractual allocation of usage risk.
- Indexation applied using a generic inflation rate rather than the specific index and mechanism defined in the project agreement.
- Bidder models in a tender evaluation built on inconsistent discount rate, inflation, or base date conventions, distorting the government agency's comparison between bids.
Recommended Evidence¶
A completed PPP model review should be accompanied by a payment mechanism cross-check against the project agreement, a deduction mechanism stress test, and a red flag report documenting any structural issue found. The table above is structured for direct use in model governance documentation, a tender evaluation file, or an audit working-paper file supporting a financial close or bid evaluation decision.
How to Use This Checklist¶
Apply the Lender Model Review Checklist first for general debt and covenant mechanics, then work through this checklist with the project agreement open alongside the model, cross-checking each contractual mechanism individually rather than relying on the model's own labelling. Where evaluating multiple bidders, apply the checklist identically to each model before comparing outputs. See Financial Model Audit for Infrastructure for industry context and Government Agency Compares Bidder Financial Models Fairly in a Tender for an applied example.
Continue Reading¶
Related Pillars¶
Related Industries¶
Related Checklists¶
- Lender Model Review Checklist
- Renewable Energy Model Checklist
- Real Estate Development Model Checklist
Related Case Studies¶
Related Resources¶
Related Products¶
How OXXON tests thisRun a free structural check with FMAE
Frequently Asked Questions
What is a PPP model, and how does it differ from a standard project finance model?
A public-private partnership (PPP) or concession model is built around a long-term contract with a public sector authority, typically including availability payment or demand risk revenue mechanisms, a defined concession term, and specific handback conditions at contract end, none of which appear in a standard corporate or merchant project finance model.
What is an availability payment mechanism, and why does this checklist test it closely?
A revenue structure where the public authority pays based on the asset being available to a defined performance standard, with deductions for failures. This checklist verifies deductions are calculated as live formulas that actually respond to modelled performance failures, not just present in a passing base case.
What is demand risk, and how does it differ from availability risk in a PPP model?
Demand risk means revenue depends on actual usage (e.g. toll traffic); availability risk means revenue depends only on the asset being available regardless of usage. Many PPP structures blend or allocate elements of both, and the model should reflect the actual contractual allocation.
What is concession life, and why does it matter for model audit?
The defined term of the PPP contract, after which the asset is handed back to the public authority. It directly determines the cash flow period available to repay debt and generate equity returns, and an incorrect concession-life assumption misstates the entire model.
What are handback conditions, and how are they checked?
Contractually defined condition standards the asset must meet at the end of the concession term, often requiring a reinvestment or maintenance reserve in the final years. This checklist verifies handback costs are explicitly modelled, not omitted from the terminal cash flow.
Who typically uses this checklist?
Government agencies evaluating bidder models in a tender process, lenders financing a PPP concession, sponsors preparing a bid model, and advisors conducting an independent structural review.
How does this checklist relate to the lender model review checklist?
The lender model review checklist covers general project finance debt and covenant mechanics. This checklist adds PPP-specific contract mechanics — availability payments, demand risk allocation, concession life, and handback — layered on top of those same debt mechanics.
Can this checklist be used to compare multiple bidders' models in a tender?
Yes. Applying the same checklist consistently across competing bidder models helps a government agency identify where bidders have used inconsistent modelling conventions that could distort a fair comparison.
Related Articles
What Is a Financial Model Audit?
A financial model audit is an independent, structured examination of an Excel based financial model to confirm that its mechanics, logic, and outputs are reliable enough to support a decision. It is not a check of whether the assumptions are optimistic or conservative. It is a check of whether the model actually calculates what its author believes it calculates. Every year, lenders extend debt, investment committees approve capital, and boards sign off on transactions using numbers that came out of a spreadsheet nobody outside the immediate deal team has independently verified. A financial model audit exists to close that gap before it becomes expensive.
What Is a Project Finance Model Audit?
A project finance model audit is a financial model audit applied to the specific class of model used to finance infrastructure, energy, and long dated capital projects: debt sculpted, multi decade, cash flow driven structures with mechanics that do not appear in a typical corporate model. It is frequently a formal condition of financial close, not an optional check, and lender requirements for it exist almost entirely inside non public bank credit policy rather than any single consolidated public source. This page defines what makes project finance models structurally distinct, why lenders require independent verification of them specifically, and what the audit process looks like in this context.
Audit vs Validation — What's the Difference?
Financial model audit and model validation are frequently used as interchangeable terms, and specifying the wrong one in a lender requirement or an internal policy leads to real confusion about what has actually been checked. They test different things. An audit tests whether a model's mechanics are correct. Validation tests whether the model's methodology and assumptions are appropriate for its intended purpose. Both are legitimate, useful exercises. They are not substitutes for each other.