Estimate estimate at completion distribution

Turn bottom-up component actuals and locally calibrated remaining-cost p50/p90 estimates into a correlated Gaussian-copula lognormal estimate-at-completion distribution with antithetic simulation, budget-breach probability, CVaR, correlation uplift, finite-draw error, and exactly reconciled component tail contributions.

What it's for

Extends Gitrevio's probabilistic forecasting promise from task duration into finance-grade bottom-up p10/p50/p75/p90 EAC, budget-breach, and shared-shock ranges.

What you give it

Inputs split into evidence read from your connected systems, calibration your team owns, and numerical controls that affect precision but never the result's meaning.

Field Type Role Required
budget_at_completion number ≥ 0 Your calibration Yes
components array of objects (4 fields) ≥ 2 items Evidence Yes
correlations array of objects (4 fields) Evidence Yes
max_detail_rows integer ≥ 1, ≤ 500 Numerical control Optional
maximum_budget_breach_probability number ≥ 0, ≤ 1 Your calibration Optional
maximum_cvar_eac number ≥ 0 Your calibration Optional
seed integer ≥ 0, ≤ 4294967295 Numerical control Optional
simulation_draws integer ≥ 1000, ≤ 200000 Numerical control Optional
tail_probability number > 0, ≤ 0.5 Your calibration Optional

Each components record

Field Type Required
actual_cost_to_date number (≥ 0) Yes
id string (non-empty) Yes
remaining_cost_p50 number (> 0) Yes
remaining_cost_p90 number (> 0) Yes
Example input
{
  "budget_at_completion": 200,
  "components": [
    {
      "actual_cost_to_date": 10,
      "id": "backend",
      "remaining_cost_p50": 50,
      "remaining_cost_p90": 100
    },
    {
      "actual_cost_to_date": 10,
      "id": "migration",
      "remaining_cost_p50": 50,
      "remaining_cost_p90": 100
    }
  ],
  "correlations": [
    {
      "correlation": 0.8,
      "id": "shared-delivery-shock",
      "left_component_id": "backend",
      "right_component_id": "migration"
    }
  ],
  "maximum_budget_breach_probability": 0.5,
  "seed": 17,
  "simulation_draws": 5000
}

What you get back

This is the actual output of running the example above — computed by the same function the platform calls, not an illustration.

Example output
{
  "component_tail_contributions": [
    {
      "actual_cost_to_date": 10,
      "component_id": "backend",
      "eac_tail_contribution": 137.7581,
      "simulated_expected_remaining_cost": 57.8136,
      "submitted_remaining_cost_p50": 50,
      "submitted_remaining_cost_p90": 100
    },
    {
      "actual_cost_to_date": 10,
      "component_id": "migration",
      "eac_tail_contribution": 137.2535,
      "simulated_expected_remaining_cost": 57.7918,
      "submitted_remaining_cost_p50": 50,
      "submitted_remaining_cost_p90": 100
    }
  ],
  "decision": "estimate_at_completion_clears_governed_risk_gates",
  "failed_gates": [],
  "guardrails": [
    "P50/P90 inputs must be calibrated on immutable estimates and later resolved component costs from this organization; Git activity is not a cost distribution.",
    "The Gaussian copula preserves the submitted pair dependence but one lognormal component cannot represent multimodal scope change, cancellation, or omitted discrete risk events.",
    "Correlation uplift is a model comparison, while component tail contribution is risk accounting; neither is causal credit, blame, or an employment signal.",
    "This bottom-up forecast complements rather than silently replaces earned-value CPI/SPI, contractual commitments, or finance-approved rebaselines."
  ],
  "method": "bottom_up_gaussian_copula_lognormal_eac_simulation_v1",
  "simulation_diagnostics": {
    "antithetic_draws": true,
    "dkw_cdf_probability_error_bound_95": 0.0192,
    "minimum_correlation_eigenvalue": 0.2,
    "seed": 17,
    "submitted_p50_is_lognormal_median": true,
    "submitted_p90_sets_lognormal_scale": true
  },
  "summary": {
    "actual_cost_to_date": 20,
    "budget_at_completion": 200,
    "component_count": 2,
    "correlation_uplift_at_p90": 16.0894,
    "cvar_eac": 275.0116,
    "expected_eac": 135.6055,
    "p10_eac": 72.9268,

Truncated for display — the full payload is 58 lines.

How it works

Forecasting & survival — Estimate when something completes or fails, with censoring and unresolved work handled honestly rather than dropped.

  1. 1 Freeze the scope baseline and actual cost to date, calibrate each component remaining-cost median and p90 on comparable resolved work, and assemble a point-in-time positive-semidefinite dependence matrix from shared delivery and market shocks.
  2. 2 Convert each p50/p90 pair into a lognormal marginal, join marginals with the Gaussian copula, use seeded antithetic Monte Carlo to simulate total EAC, and compare its p90 with the same marginals under independence.
  3. 3 Report EAC quantiles, breach probability, CVaR, a DKW finite-draw probability bound, and component tail accounting; apply probability and CVaR gates without overwriting earned-value, contractual, or rebaseline evidence.

Before you trust it

Every tool in the catalog ships with the conditions under which its answer is meaningful — and the conditions under which it should abstain instead of guessing.

Assumptions & guardrails

  • Training examples precede their outcomes, censoring and unresolved work are represented, and deployment populations remain comparable to validation cohorts.
  • Component scope is exhaustive and non-overlapping; actual costs are finance-reconciled; p50/p90 estimates are calibrated without leakage; the lognormal marginal and Gaussian copula are adequate; dependence is PSD; and discrete cancellation, scope-change, and contractual risks are separately represented.
  • A predictive interval or risk estimate is not a deadline promise, causal explanation, or individual-performance judgment.
  • This is a bottom-up cost forecast—not a deterministic commitment, a replacement for accepted earned value or contracts, or a productivity/performance score; component tail contribution is dependence-sensitive risk accounting rather than causal blame.

Minimum evidence

  • components: at least 2 rows/items
  • correlations: required and organization-defined
  • budget_at_completion: required and organization-defined

How to validate it

Use chronological train/calibration/test windows, compare proper scores and decision value with a simple baseline, and recalibrate only from outcomes resolved after prediction time.

Calibrating it to your org

Same for everyone

The mathematical kernel, validation rules, method version, and JSON output semantics are organization-independent; no tenant-trained coefficients or company benchmark is embedded in the function.

Specific to you

  • tenant-local p50/p90 calibration from point-in-time component estimates paired with later finance actuals, plus a PSD shared-shock dependence model and discrete-risk completeness audit
  • component perimeter/non-overlap, currency/horizon, actual-cost cutoff, scope/rebaseline policy, work classes, marginal family, dependence epoch, budget, risk gates, draws, seed, and finance/PMO ownership

Calibration workflow

  1. 1 Define the management decision, target outcome, aggregate unit, privacy boundary, cadence, and prediction/intervention horizon for this organization.
  2. 2 Build a tenant-scoped historical cohort using only information available before each prediction or decision; preserve zero periods, censoring, assignment probabilities, and unresolved outcomes when the method requires them.
  3. 3 Estimate statistical parameters on training history, but obtain costs, utilities, risk tolerance, practical-effect thresholds, capacity, and policy constraints from accountable decision owners.
  4. 4 Validate on later time windows or held-out aggregate units at the deployment grain, against a simple baseline and the function-specific validation strategy.
  5. 5 Deploy only if the returned decision clears evidence, overlap, calibration, robustness, and guardrail checks; warning, unsupported, schema-gap, and fallback decisions are abstentions.
  6. 6 Monitor realized outcomes, data drift, coverage, and decision regret; recalibrate at a governed cadence or after a detected regime/definition change, never merely because a stakeholder dislikes the result.

Call it from your AI

You don't wire up 388 tools in your MCP client. The GitRevio MCP server exposes 18 tools, three of which let an agent search the catalog, read a tool's schema, and run it — so the assistant finds this one on its own.

gitrevio_capabilities_search
  { "q": "turn bottomup component actuals and locally" }
  → finds "estimate_estimate_at_completion_distribution"

gitrevio_capability_describe
  { "capability_id": "estimate_estimate_at_completion_distribution" }
  → returns the input schema and agent guidance shown on this page

gitrevio_capability_run
  { "capability_id": "estimate_estimate_at_completion_distribution", "arguments": { ... } }
  → returns the result shown above

Works in Claude Desktop, Claude Code, Cursor, Cline, Continue.dev, Goose and Aider. See the MCP server.

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