Glossary

Patient Days

Patient days, also called inpatient days, is the total count of days patients occupy a hospital bed over a defined period, calculated by summing each admitted patient's length of stay across all discharges in that period. Patient days is the base unit against which occupancy rate, staffing ratios, per-diem cost and revenue, and many other healthcare financial model calculations are built, making it one of the most frequently referenced volume metrics in a hospital or facility-level model.

Payback Period

Payback period is the length of time required for a project's cumulative cash flows to recover the initial investment. It exists in two forms — simple payback, which ignores the time value of money, and discounted payback, which discounts each cash flow before accumulating it. Payback period measures capital-recovery speed and liquidity risk rather than value creation, and its principal weakness — shared by both forms — is that it ignores every cash flow occurring after the payback threshold is reached, regardless of its magnitude.

Payer Mix

Payer mix is the distribution of a healthcare provider's patient volume, and more importantly its revenue, across payer categories such as government programmes, commercial insurance, managed care, and self-pay patients. Because each payer category reimburses the same clinical service at a materially different rate, payer mix is one of the primary determinants of a healthcare provider's realised revenue per case, independent of both volume and case mix index. A financial model that assumes a single blended reimbursement rate across all patients, rather than modelling payer mix explicitly, understates its sensitivity to a shift in that mix.

Perpetuity Growth Rate

The perpetuity growth rate (also called the terminal growth rate or Gordon growth rate) is the assumed constant rate at which a business's free cash flow is expected to grow indefinitely beyond the explicit forecast period. It is the key assumption in the Gordon Growth Model method of calculating terminal value, and it must be strictly less than the discount rate for the perpetuity formula to produce a finite, meaningful value. Because no business can outgrow the broader economy forever, the perpetuity growth rate is conventionally capped at or near the long-run expected growth rate of GDP or inflation in the business's operating geography.

Physical Climate Risk

Physical climate risk is the direct financial risk that climate hazards, whether sudden events or gradual change, pose to physical assets, operations, or supply chains. It is conventionally split into acute physical risk, event-driven disruption such as a flood or storm, and chronic physical risk, gradual change such as rising average temperature or sea level, since the two carry different timing, probability, and mitigation characteristics.

Power Query

Power Query is Microsoft's data connectivity and preparation engine, built into Excel and other Microsoft products, used to connect to a data source, apply a recorded sequence of transformation steps, and load the result into the workbook. In financial modelling, Power Query is typically used to ingest and clean external data — an accounting system export, a data room file, a market data feed — before that data reaches the model's calculation layer, replacing what would otherwise be a manual copy-paste-and-clean step performed by hand each time the source data updates.

Power Usage Effectiveness (PUE)

Power usage effectiveness (PUE) is calculated as total facility power divided by critical IT load power, with a value approaching 1.0 indicating that nearly all power consumed is delivered to IT equipment rather than lost to cooling, power distribution, and other non-IT overhead. PUE is the standard industry measure of data centre power efficiency, and because power is typically one of the largest operating cost categories, a facility's PUE directly drives its power cost per unit of billable capacity and, in turn, its profitability.

Precedent Transaction

Precedent transaction analysis values a business by applying multiples paid in comparable historical M&A transactions to the subject company's own financial metrics. Because these multiples reflect what an acquirer actually paid to gain control of the target, they embed a control premium that comparable company (trading comps) multiples do not. Precedent transactions also embed deal-specific dynamics — synergies, competitive tension, and prevailing market conditions at the time of the deal — that do not always generalize to a new transaction, and the available transaction set for a given sector or time period can be thin or stale.

Production Decline Curve

A production decline curve is a mathematical function, exponential, hyperbolic or harmonic, describing how upstream oil and gas production output falls over time from an initial rate as a reservoir depletes. It is the central structural basis for upstream revenue and debt capacity projection, and its parameters must be kept consistent with the underlying reserve engineering report, a recurring source of divergence and audit finding when the two are maintained separately.

Production Sharing Contract

A production sharing contract (PSC) is a fiscal arrangement, common in many oil and gas jurisdictions, under which the host government retains ownership of the resource while the contractor bears exploration and development risk in exchange for cost recovery from a capped share of production and a further split of remaining, "profit," production against the government. PSC mechanics vary materially by jurisdiction and require dedicated modelling of the actual contract formula rather than a generic effective tax rate.

Profitability Index (PI)

The profitability index (PI) is the present value of a project's future cash flows divided by its initial investment, equivalently expressed as 1 plus NPV divided by the initial investment. Unlike NPV, which is stated in absolute currency terms, the profitability index is a ratio, which makes it particularly useful for ranking competing projects by capital efficiency when a company faces capital rationing and cannot fund every positive-NPV project available to it.

Project Finance Model

A project finance model is a financial model built to analyse the economics of a capital project that is financed on a non-recourse or limited-recourse basis. In a non-recourse structure, lenders rely solely on the cash flows generated by the project — and the security over the project's assets — for repayment of the debt. They have no recourse to the equity sponsors' wider balance sheets. The project finance model is the primary analytical tool through which all parties — sponsors, lenders, advisers, and government agencies — evaluate the project's financial viability, structure the debt, negotiate terms, and, after financial close, monitor the project's ongoing financial performance.

Project IRR

Project IRR (Project Internal Rate of Return) is the internal rate of return calculated on a project's total cash flows before any financing costs — that is, before debt drawdowns, interest payments, principal repayments, and equity contributions. It represents the unlevered return of the underlying project, independent of how it is financed. Project IRR answers the question: what return does the project generate on the capital deployed in it, regardless of whether that capital is debt or equity? This distinguishes it from Equity IRR, which is calculated on cash flows net of all financing — the return received by equity investors after debt has been serviced. The Project IRR formula is the same as the standard IRR formula: Where: - C_t is the total project cash flow in period t (pre-financing) - r is the Project IRR In Excel: XIRR is the correct function for project finance applications where cash flows occur at irregular intervals.

Prompt Engineering

Prompt engineering is the practice of structuring the instructions, context, and constraints given to a generative AI model in order to produce more reliable, relevant, and verifiable output for a specific task. In a finance context, effective prompt engineering typically includes stating the required output format, providing the specific source data to draw on, and explicitly instructing the model to flag rather than fabricate any information it cannot verify.

Proved and Probable Reserves

Proved (1P), proved plus probable (2P), and proved plus probable plus possible (3P) reserves are the standard classification system, set out in the Petroleum Resources Management System, for the certainty of estimated recoverable hydrocarbon volumes. Which category is appropriate depends on the model's purpose: reserve-based lending typically sizes against proved reserves alone, while planning models sometimes incorporate 2P volumes, and using the wrong category for a given purpose materially distorts the resulting analysis.

Provision Coverage Ratio

The provision coverage ratio measures the allowance for credit losses against non-performing loans, indicating how well a bank's accumulated provisions cover the problem exposure it has already recognized. A low or declining coverage ratio, particularly alongside a rising non-performing loan ratio, signals that reserves may be insufficient relative to recognized risk — a combination that should prompt closer review rather than being read from either ratio alone.

Purchase Price Allocation

Purchase price allocation (PPA) is the process, required under both IFRS and US GAAP acquisition accounting, of allocating the price paid for an acquired business between its identifiable net assets, recorded at fair value as of the acquisition date, and goodwill, the residual representing value the acquirer paid beyond those identifiable assets. The allocation directly determines the combined entity's post-transaction depreciation and amortization, since revalued tangible assets and newly recognized intangible assets each carry their own schedule going forward, distinct from goodwill, which is not amortized but is tested periodically for impairment.

Quality of Earnings

Quality of earnings (QoE) analysis is the central financial due diligence deliverable — a detailed reconciliation from a target's reported EBITDA to a normalized figure, removing one-off items, non-recurring items, and non-operational items to arrive at a figure that more reliably represents sustainable, ongoing earnings. Because the resulting normalized EBITDA is typically the earnings base a transaction's valuation multiple is applied to, an unsupported or aggressive quality of earnings adjustment has a direct, dollar-for-dollar effect on the price paid.

Rack Density

Rack density measures how much power a tenant's rack draws, expressed in kW per rack, and by extension how much heat must be removed by the facility's cooling system to support it. Rising rack density, driven by higher-performance computing equipment, is the primary reason power and cooling capacity, rather than floor space, increasingly bind data centre capacity before floor space is exhausted, and density tier is a primary basis for colocation pricing.

Real vs. Nominal Cash Flow

Real cash flow is expressed in constant purchasing-power terms, stripped of the effect of expected future inflation, while nominal cash flow includes that inflation effect and reflects the actual currency amounts expected to be received or paid in each future period. The distinction matters in DCF valuation because the discount rate must be built on the same basis as the cash flow it discounts — a nominal discount rate, which embeds an inflation expectation, must be applied to nominal cash flows, and a real discount rate must be applied to real cash flows. Mixing the two bases, most commonly by discounting nominal cash flows at a real rate, is one of the more subtle and consequential structural errors in DCF valuation.