The Ocelot project is a joint effort by the Paul Scherrer Institut and the ecoinvent centre to build an open source library for applying system models in life cycle assessment. System models are a set of linking rules and assumptions, including how to handle activities that produce multiple outputs, how to construct markets in time and space, what products are substitutable, and who gets credit for the production of recyclable materials.


There are currently a large number of system models used both in life cycle assessment, and in environmental product declarations and footprinting. For example, the ecoinvent centre releases three different versions of the ecoinvent database, each with their own system model. We know that the uncertainty due to these modelling choices is significant. However, it has been almost impossible to examine all the explicit and unspoken assumptions and choices that each system model includes.

A new approach

The Ocelot project aims to provide a new approach to this problem through a combination of documentation and software. Initially, we will document and implement the cut-off and long-term consequential system models from ecoinvent 3.2. Users will also be able to modify these models or create their own. As the importance of LCA continues to grow, the scrutiny and pressure on the scientific basis of LCA will also increase. Providing transparent and flexible linking algorithms will allow the Ocelot team and the research community to systematically test the robustness of system models. Such tests include isolating the effects of individual choices, the effects of different assumptions, and how appropriate certain assumptions are for various sectors of the economy.

A public project, open to all

The Ocelot project isn't making software specific to ecoinvent - our intention is that Ocelot can be used on any source of raw, unallocated data, provided that the data can be converted to a suitable form. The internal data format of Ocelot is simple and well documented.

We would very much appreciate feedback on Ocelot from the LCA and footprinting communities. Are there any particular choices you like or disagree with, or options that you have wanted to test but haven't had the means? Please let us know, and we will try to include it! Please add your suggestions to the general wiki for Ocelot capabilities.

In addition to this webpage, Ocelot has a development blog, an open science framework page, online documentation, and of course open source code on Github.

Ocelot development

Ocelot source code and documentation is on Github, including milestones and deadlines.

Phase one of the Ocelot project will run from spring to fall 2016, and is funded by the Swiss Commission for Technology and Innovation.