Book 2

Performance Modeling
and Forecasting

The standards for how early-stage companies must build financial forecasts, measure unit economics, model growth, stress-test assumptions, and manage cost structure.

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Book 2 governs the quality, methodology, and completeness of financial forecasting and performance analysis. A financial model that is structurally compliant with Book 1 but built on arbitrary growth rates, revenue-based lifetime value, and single-scenario projections does not provide the decision-making utility or investor credibility that compliant financial infrastructure requires. Book 2 defines what the model must contain, how the forecasts must be constructed, and what analysis must accompany them.

Section 2.1

The Forecasting Methodology Standard

A compliant forecast is a bottom-up forecast constructed from granular operational assumptions. It is distinct from the annual operating plan, which is the accountability reference. The forecast represents the company's current probability estimate for future performance and is updated continuously. The plan is fixed at approval.

Compliance criteria

Level 1
A bottom-up revenue forecast exists with documented operational assumptions. The forecast period covers a minimum of twelve forward months. Key assumptions are separated from outputs.
Level 2
All Level 1 criteria met. The forecast period covers a minimum of twenty-four months. A rolling forecast is maintained and updated monthly. Forecast accuracy is tracked against the forecast prepared at least one month in advance for each completed period. The growth model is specific to the company type: B2B Enterprise uses a pipeline model and sales capacity model; Recurring Revenue uses a subscription growth model; Product-Led Growth uses activation and conversion rates.
Level 3
All Level 2 criteria met. The forecast integrates with the annual operating plan such that plan-versus-forecast variance is reported monthly. Forecast assumptions are reviewed and formally updated quarterly by the board.
Section 2.2

The Unit Economics Standard

Unit economics are the direct financial metrics associated with a single commercial unit. The unit definition must be documented and applied consistently. Lifetime value must be calculated using gross profit, not revenue. Customer acquisition cost must be fully loaded, including all personnel costs. The LTV to CAC ratio is only valid when both sides use consistent cost treatment.

Compliance criteria

Level 1
The company has calculated its customer acquisition cost on a fully loaded basis and its gross-profit-based lifetime value. The payback period is known. The unit definition is documented.
Level 2
All Level 1 criteria met. Lifetime value is calculated using cohort analysis, not an assumed average lifespan. Net revenue retention and gross revenue retention are reported separately and updated monthly. The churn rate is calculated at both customer and revenue level. Unit economics are segmented by company type, customer segment, or acquisition channel where material differences exist.
Level 3
All Level 2 criteria met. Unit economics are tracked at cohort level across at least twelve rolling months of customer cohorts. Deteriorating unit economics across successive cohorts are flagged to the board within the period in which the deterioration is first observable.

Key ratios and benchmarks

  • LTV to CAC ratio of 3 or above: generally considered sustainable at Growth Stage for a recurring revenue business
  • Payback period of 12 months or fewer: generally considered efficient at Growth Stage
  • Burn multiple below 1: the company generates more new recurring revenue than cash it consumes
  • Magic number above 1: each pound of prior-period sales and marketing spend generates more than one pound of new annualised recurring revenue
Section 2.3

The Growth Modeling Standard

A growth model is not a growth rate. It is a structured representation of the specific operational mechanisms by which the company acquires customers and generates revenue. Applying a single percentage growth rate to revenue without specifying the mechanism that produces it does not satisfy this Standard.

Growth model requirements by company type

  • B2B Enterprise: Pipeline model with stage-specific conversion rates calibrated against historical data, combined with a sales capacity model accounting for ramp periods and quota attainment rates
  • Recurring Revenue SaaS: Subscription growth model tracking new additions, expansions, contractions, and churn monthly, with monthly recurring revenue as the primary output
  • Product-Led Growth: Activation funnel model driven by registered user volume, activation rate, conversion rate from free to paid, and expansion mechanics
  • B2C Consumer: Cohort-based acquisition model tracking customer additions by channel with channel-specific acquisition cost and retention curves
  • Transactional Revenue: Volume and frequency model tracking active users, transaction frequency, and average transaction value
Section 2.4

The Scenario and Sensitivity Analysis Standard

A compliant scenario analysis contains at minimum a base case and a downside case, each internally consistent. Internal consistency means the revenue assumptions, cost structure, and hiring plan within each scenario are coherent with each other. A downside scenario that reduces revenue without reducing costs is not internally consistent and does not satisfy this Standard.

Sensitivity analysis measures the change in a single output from a change in a single input. It identifies which assumptions drive the most risk in the forecast. Sensitivity analysis and scenario analysis are complementary, not interchangeable.

Compliance criteria

Level 1
A base case and downside case exist. Both are internally consistent. The downside case includes a management cost response to the lower revenue. The cash runway impact of the downside case is calculated.
Level 2
All Level 1 criteria met. An upside case is also maintained. Sensitivity analysis is performed on the three to five most material assumptions in the base case. The sensitivity output is presented to the board as part of quarterly financial review.
Level 3
All Level 2 criteria met. Scenario switching is automated in the model. Probability weightings are assigned to each scenario and updated quarterly. The weighted average cash runway across scenarios is reported to the board.
Section 2.5

The Cost Structure Standard

A compliant cost structure analysis tracks the relationship between revenue growth and cost growth over time, identifies where operating leverage exists, and models how gross margin is expected to evolve as the company scales. Projecting margin expansion without identifying the specific mechanism that produces it is a deficiency under this Standard.

Compliance criteria

Level 1
Gross margin is calculated correctly and reported monthly. The cost of goods sold definition is documented and applied consistently. Personnel cost uses fully loaded cost.
Level 2
All Level 1 criteria met. The Rule of 40 score is calculated and tracked quarterly. The burn multiple is tracked monthly. Operating leverage is modeled explicitly: the forecast shows the specific cost line items expected to scale sublinearly with revenue and the basis for that expectation.
Level 3
All Level 2 criteria met. Cost structure is reviewed annually against industry benchmarks by company type and stage. A formal cost efficiency program exists with named owners and measurable targets for each functional area.

Common Deficiencies in Book 2

  • The revenue forecast applies a single growth rate to the prior period's revenue without specifying the sales capacity, pipeline, or acquisition mechanism that produces it. The model is top-down in substance regardless of how it is described.
  • Lifetime value is calculated using total revenue per customer rather than gross profit, and using an assumed average lifespan rather than observed cohort retention. The resulting LTV to CAC ratio overstates unit economics by a material factor.
  • Customer acquisition cost excludes sales and marketing personnel costs, using only advertising spend or agency fees. For most early-stage companies this understates the true acquisition cost by fifty percent or more.
  • The financial model contains only a base case. No downside scenario exists. The board has not considered the cash runway implications of a revenue shortfall.
  • The downside scenario reduces revenue assumptions but leaves the cost structure unchanged, producing a scenario that is not internally consistent and does not represent a plausible management response to lower revenue.
  • Net revenue retention and gross revenue retention are conflated. A net revenue retention figure above one hundred percent is reported as gross retention, misrepresenting the underlying churn dynamics.
  • The sales capacity model assumes new sales hires are immediately productive from their start date. No ramp period is modeled, overstating near-term revenue contribution of planned hires by the full quota amount for the ramp duration.
  • Margin expansion is projected in the financial model without any identified operating leverage mechanism. The forecast shows improving gross margins across the projection period with no structural change in cost of goods sold to explain the improvement.

Citable URL

https://ffistandard.org/standard/book-2-performance-modeling/

Full citation: Founder Financial Infrastructure Standard, Beta v0.5, Book 2. ffistandard.org. 2026.

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Book 1: Financial Architecture Book 3: Capital Structure