> ## Documentation Index
> Fetch the complete documentation index at: https://docs.appliedaifoundation.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Methodology explorer

> In-app calculators and reference tables for CII, EU ETS, and FuelEU.

The Methodology page is the platform's built-in classroom. It explains each calculation in plain language and gives you interactive calculators so you can sanity-check inputs without spreadsheet wrangling.

<Frame caption="Methodology explorer — three tabs: CII, EU ETS, FuelEU.">
  <img src="https://mintcdn.com/metaweaveconsultant/ZChQsW2FZuO2wFx2/images/methodology/hero.png?fit=max&auto=format&n=ZChQsW2FZuO2wFx2&q=85&s=9e29ce8616de9dd82b73b9ab89d71725" alt="Methodology explorer" width="2880" height="5076" data-path="images/methodology/hero.png" />
</Frame>

## Three tabs

### CII tab

<Frame caption="CII tab with Required and Attained calculators.">
  <img src="https://mintcdn.com/metaweaveconsultant/ZChQsW2FZuO2wFx2/images/methodology/cii-tab.png?fit=max&auto=format&n=ZChQsW2FZuO2wFx2&q=85&s=096653fbcdba07cec01af96077e47640" alt="CII tab" width="2880" height="5076" data-path="images/methodology/cii-tab.png" />
</Frame>

* Plain-language explanation of CII and the A–E rating scale
* Reference-line formula `CII_ref = a × Capacity^(-c)` with a explanation of `a` and `c` per ship type
* **Required CII calculator** — enter ship type, capacity, year → get the required value and reduction factor for that year
* **Attained CII calculator** — enter CO₂, capacity, distance → get attained CII plus the corresponding rating

### EU ETS tab

<Frame caption="EU ETS tab with calculator.">
  <img src="https://mintcdn.com/metaweaveconsultant/ZChQsW2FZuO2wFx2/images/methodology/ets-tab.png?fit=max&auto=format&n=ZChQsW2FZuO2wFx2&q=85&s=31ba92d1c2c5f746494693849e8ef0e2" alt="EU ETS tab" width="2880" height="5076" data-path="images/methodology/ets-tab.png" />
</Frame>

* Voyage classification table and coverage factors
* Phase-in schedule (40% / 70% / 100%)
* **EU ETS calculator** — enter voyage CO₂, voyage type, year, EUA price → get coverage %, phase-in factor, ETS emissions, and EUR cost

### FuelEU tab

<Frame caption="FuelEU tab with WtW calculator.">
  <img src="https://mintcdn.com/metaweaveconsultant/ZChQsW2FZuO2wFx2/images/methodology/fueleu-tab.png?fit=max&auto=format&n=ZChQsW2FZuO2wFx2&q=85&s=5e87cd7d00694ecfbaedc23d4b25bf4b" alt="FuelEU tab" width="2880" height="5076" data-path="images/methodology/fueleu-tab.png" />
</Frame>

* Plain-language WtW = WtT + TtW explanation
* Full reduction pathway 2025–2050
* Annex II default emission factors for every supported fuel
* **FuelEU calculator** — enter fuel type, tonnes, year → get WtT, TtW, WtW, fleet-equivalent intensity, compliance status, and projected penalty

## What you can do here

* Verify numbers from the dashboard against a manual calculation
* Train new team members on the regulatory mechanics
* Model what-if scenarios before committing data: "what would CII look like if we bunkered 200 t of LNG instead of HFO?"
* Reference the official formulas without leaving the platform

## Source

UI under `src/app/methodology/`. Calculator inputs reuse the same calculation utilities (`ciiCalculator.ts`, `fuelEUCalculator.ts`, `portClassifier.ts`) that power the production dashboard — there's no separate "demo" code path.