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

# Methods and Models

> Explore the 3 key Life Cycle Assessment (LCA) methods businesses actually use – EF 3.1, IPCC 2021, and ReCiPe 2016, plus allocation frameworks like EN 15804 and consequential modelling.

## **Why Sustainly Focuses on 3 Proven LCA Methods**

After speaking with hundreds of specialists, we saw the same pattern: while databases like Ecoinvent list 40+ options, in practice companies are aligning around just a few. That's why we give you the ones that matter most

## Methods you'll see

<Steps>
  <Step title="EF 3.1 Environmental Footprint🌍" />

  <Step title="IPCC 2021 Intergovernmental Panel on Climate Change♻️" />

  <Step title="ReCiPe 2016🧪" />
</Steps>

## Methods at a glance

| Method          | Focus                                                | Indicators | Extras                                   |
| --------------- | ---------------------------------------------------- | ---------- | ---------------------------------------- |
| **EF 3.1**      | Multi-indicator across climate, human health, nature | 16         | Normalisation and weighting              |
| **IPCC 2021**   | Carbon footprint detail                              | >30        | Short and long term GWP view             |
| **ReCiPe 2016** | Understandable, comparable analyses                  | 18         | Endpoints: health, ecosystems, resources |

## Allocation Methods and Frameworks

As if the variability of different methodologies were not enough, you also have to consider which allocation method and framework to use.

**Attributional modelling (the raw contribution).**\
Most common for product studies and used to create both EPDs and PEFs. It totals the direct contribution of all lifecycle stages (e.g., wheat → milling → baking → delivery for a loaf of bread).

**Consequential modelling (measuring context).**\
Used more in academic and large-scale analyses. Looks at system-wide effects and market dynamics (e.g., assessing a solar park’s effect on the electricity market, not only its added emissions).

**Frameworks supported.**\
Sustainly supports cut-off, EN 15804, and consequential allocation. EN 15804 (for European EPDs) notably credits future recycling in how waste is modelled.

## Why these methods matter

While different methodologies vary in their specific indicators, LCAs look beyond CO₂e and typically consider impacts on nature, human health, and resources. ReCiPe’s endpoints, in particular, make effects tangible by expressing damage to human health, ecosystems, and resource availability.