Mission Statement
ReLife is an open source Python library to optimize large-scale infrastructure investment decisions.
Description
All network managers are currently facing major challenges: renewing aging infrastructures that were installed several
decades ago, integrating new energy sources (solar, wind) and addressing the increasing need for inter-connections
between countries. All of this is happening in the context of climate change and global supply tensions. When possible, a
quantitative approach is desirable to justify investment needs for asset renewals and network development.
ReLife is an open source Python library that implements survival analysis methods, renewal theory, and socioeconomic
evaluation aimed at optimizing network asset renewal policies.
The library allows to:
- Understand and model assets behaviors through time
Users can find probability models in two modules called lifetime_model and stochastic_process that allow to:
- Model asset lifetime (lifetime distributions and regression models).
- Model recurrent minimal repairs (non-homogeneous Poisson processes)
- More to come (continuous time deterioration process, causal inference).
These models are fitted from data provided by the user.
- Compare and project future operations for different maintenance strategies along with the associated budgets
Given costs and fitted models that represent assets behavior, ReLife can model different maintenance strategies. In the
policy module, one can find:
- Corrective replacement policy, a.k.a. run-to-failure (replacement upon failure).
- Preventive age replacement policy (replacement at a predefined age or upon failure, which ever comes first).
Users can evaluate the social-economical performance of different maintenance policies by computing the expected
discounted annual costs (including the real costs of replacement and societal costs like the shadow price of carbon).
In addition, building from renewal theory, ReLife allows to project the consequences of a given maintenance policy
(upcoming expected number of replacements and budgets).
Main benefits of the library :
- Facilitate the access to open and peer-reviewed mathematical methods to make optimal decisions in asset management.
- Reduce research-to-industry gap.
- Give applied educational outreach materials in reliability theory applied to asset management.
- Give a high-level data collection standard to meet closely the requirements of statistical modelling.
- Built on Numpy and Scipy to ensure stability and accessibility.
Proposed Project Stage
Sandbox
Is this a new project or an existing one?
This is an existing project, available publically on GitHub at https://github.com/rte-france/relife.
Current lead(s)
The current lead is RTE France.
The research and math expertise is driven by Alexis FREMOND.
Implementations and development of the library are conducted by William GRISON.
Important choices are always discussed with Thomas GUILLON, the original project leader and first developer.
Sponsoring organization(s), along with any other key contributing individuals and/or organizations
Main contributions come from RTE France.
Research and developement are also supported by Artelys.
The community of users is growing. Other infrastructure managers have started using ReLife : TenneT, AusNet, GRTgaz.
Continuous efforts are made to spread the software through regular presentations to other infrastructure managers
(Airliquide, TotalEnergies and HydroQuebec), scientific conferences (MIMAR 2025), open source sponsors (NumFocus, LFE
Europe Summit 2025).
ReLife is also part of the training program for engineering students at CentraleSupélec.
Detail any existing community infrastructure, including:
- Github/GitLab, or other location where the code is hosted
- Website and/or docs
- Communication channels ( such as Mailing lists, Slack, IRC )
- Social Media Accounts
- PyPi, npm, or other App Stores maintainted by the project
ReLife is hosted under the Github organization of RTE France.
Its documentation is built with Sphinx and the PyData Sphinx theme.
ReLife has no communication channels nor social media accounts.
Are there any specific infrastructure needs or requests outside of what is provided normally by LF Energy ? If so please detail them.
ReLife can be used on any system with Python 3.11+ installed.
Why would this be a good candidate for inclusion in LF Energy?
Large-scale infrastructure investment decisions is a critical problem in the energy industry in the context of climate
change, global supply chain tensions and tight budgets. To our knowledge, ReLife is the only open source software that
implements a complete toolbox to guide decision-making in asset management through the following workflow:
- Data collection and processing.
- Probability models estimations (lifetime distributions, regression models, minimal repair procresses, etc.).
- Optimization and comparison of the performance of different maintenance policies.
- Projection of the consequences (stocks and budgets).
ReLife helps utilities improve the performance of their infrastructure by reducing risks and optimizing investments.
How would this benefit from inclusion in LF Energy?
ReLife's inclusion into LF Energy would allow it to detach its name from RTE and help with its adoption in various
industries. For example, as far as we know, several companies have shown interest in using ReLife for their asset
management needs. The lack of an open, neutral "container" such as LF Energy might be a key element in the limited
adoption of ReLife outside of RTE. We hope that the inclusion in LF Energy will leverage worldwide collaborations on
these topics, including vendors and other asset management organizations, in order to spread the software usage,
consolidate the codebase and add new functionalities.
By joining the LF Energy this project would also benefit from LF Energy's experience in managing open-source communities
and more rigorous project management.
Provide a statement on alignment with the mission in the LF Energy charter.
ReLife aims at providing an open source ecosystem to:
- Promote open science.
- Disseminate tools and knowledge.
- Ensure code transparency and auditability.
- Allow continuous improvement.
- Provide free and transparent software.
- Support reliability professionals.
- Foster collaboration (e.g. make ReLife a Linux Foundation project).
which aligns with LFE mission " LF Energy projects provide a unified approach to developing non-differentiating code
that can enable the world’s power systems to transform rapidly to electrification. LF Energy provides a neutral
leveraged development environment that can accelerate the pace of innovation and target investments in a coordinated and
efficient manner. ".
What specific need does this project address?
This project allows infrastructure manager rationalize their investment decisions to improve grid performance by
optimizing maintenance policies.
Describe how this project impacts the energy industry.
Reliability, a subfield of probability theory that studies the failure of systems, has been well documented for more
than 60 years. However, it is not widespread among utility engineers and it has been frequently obscured by rules of
thumb and black-box proprietary softwares. This can lead to poor decision-making and potentially catastrophic
consequences, as illustrated by Pacific Gas and Electric Company’s involvement in devastating wildfires linked to
inadequate asset management decisions. ReLife brings reliability into the asset management practices to reduce risks and
optimize socio-economical value.
Describe how this project intersects with other LF Energy projects/working groups/special interest groups.
To our knowledge, there are no similar LF Energy projects/working groups/special interest groups. We think that the
inclusion of ReLife to the LF Energy can motivate the creation of an special interest group focused on asset management.
Who are the potential benefactors of this project?
- Any utilities.
- Any industries willing to optimize their investment decisions.
- Research or academic organizations working on reliability and risk analysis applied to asset management.
What other organizations in the world should be interested in this project?
- Regulators.
- Any infrastructures outside the energy sector, such as railways, the automotive industry, data centers, and more.
Plan for growing in maturity if accepted within LF Energy
- Comprehensive documentation.
- Enhanced software functionalities designed to tackle additional challenges faced by asset managers, such as deterioration processes, causal inference, and imperfect repairs.
- Active participation in open source and open science communities by, for example, submitting a paper to the Journal of Open Source Software (JOSS)
- Organization of workshops to share use cases with other utilities, thereby expanding the user base.
- Foster collaborations with academics to broaden the contributor base.
Project license
The project is currently licensed under the Apache 2.0 License.
Is the project's code available now? If so provide a link to the code location.
The project's code is available at https://github.com/rte-france/relife.
Does this project have ongoing public (or private) technical meetings?
Currently, there are no public meetings. Private technical meetings are regularly organized at RTE to discuss codebase improvements.
Does this project's community venues have a code of conduct? If so, please provide a link to it?
We don't have a code of conduct yet.
Describe the project's leadership team and decision-making process.
ReLife's leadership team is both composed of mathematicians and engineers. The development follows these steps:
- Needs are identified during meetings with both internal and external asset managers.
- Research is conducted at RTE to develop the mathematical foundations necessary to address the identified problems.
- Implementations are added through pull requests, with detailed instructions available here.
- Continuous codebase reviews are performed to ensure long-term maintainability. We are progressively type-checking the
codebase using Pyright and MyPy. This process allows us to refactor the code to adhere to the highest software design standards. Additionally, we write unit tests to prevent regression.
Does this project have public governance (more than just one organization)?
This project has no public governance.
Does this project have a development schedule and/or release schedule?
ReLife has no clear development schedule and/or release schedule.
Does this project have dependencies on other open source projects? Which ones?
ReLife is written in Python. In a near future, it is possible that we incorporate Cython code to bind computations to C
code.
To run it on a computer, users need to install python3 (version 3.11 or greater). The following dependencies are
automatically installed:
Describe the project's documentation.
The document is composed of the following parts:
- Installation. How to install ReLife ?
- Basics. ReLife absolute basics for beginners.
- User guide. An overview of ReLife important features.
- API. The exposed ReLife API, i.e. a currated list of objects public interfaces.
- For developers. Under-the-hood documentation for contributors.
Each part of the documentation may evolve in the future.
Describe any trademarks associated with the project.
There are no current trademarks associated with the project.
Do you have a project roadmap? If so please attach or provide a link.
We don't have a public project roadmap.
Are this project's roadmap and meeting minutes public posted?
We do not publish a project roadmap nor organize meeting minutes publically.
Does this project have a legal entity and/or registered trademarks?
This project has no legal entity and registered trademarks. However, if possible, we do want to keep the project under
the name of "ReLife" (reliability + lifetime).
Has this project been announced or promoted in any press?
ReLife has been promoted at :
Does this project compete with other open source projects or commercial products?
Not to our knowledge.
Mission Statement
ReLife is an open source Python library to optimize large-scale infrastructure investment decisions.
Description
All network managers are currently facing major challenges: renewing aging infrastructures that were installed several
decades ago, integrating new energy sources (solar, wind) and addressing the increasing need for inter-connections
between countries. All of this is happening in the context of climate change and global supply tensions. When possible, a
quantitative approach is desirable to justify investment needs for asset renewals and network development.
ReLife is an open source Python library that implements survival analysis methods, renewal theory, and socioeconomic
evaluation aimed at optimizing network asset renewal policies.
The library allows to:
Users can find probability models in two modules called
lifetime_modelandstochastic_processthat allow to:These models are fitted from data provided by the user.
Given costs and fitted models that represent assets behavior, ReLife can model different maintenance strategies. In the
policymodule, one can find:Users can evaluate the social-economical performance of different maintenance policies by computing the expected
discounted annual costs (including the real costs of replacement and societal costs like the shadow price of carbon).
In addition, building from renewal theory, ReLife allows to project the consequences of a given maintenance policy
(upcoming expected number of replacements and budgets).
Main benefits of the library :
Proposed Project Stage
Sandbox
Is this a new project or an existing one?
This is an existing project, available publically on GitHub at https://github.com/rte-france/relife.
Current lead(s)
The current lead is RTE France.
The research and math expertise is driven by Alexis FREMOND.
Implementations and development of the library are conducted by William GRISON.
Important choices are always discussed with Thomas GUILLON, the original project leader and first developer.
Sponsoring organization(s), along with any other key contributing individuals and/or organizations
Main contributions come from RTE France.
Research and developement are also supported by Artelys.
The community of users is growing. Other infrastructure managers have started using ReLife : TenneT, AusNet, GRTgaz.
Continuous efforts are made to spread the software through regular presentations to other infrastructure managers
(Airliquide, TotalEnergies and HydroQuebec), scientific conferences (MIMAR 2025), open source sponsors (NumFocus, LFE
Europe Summit 2025).
ReLife is also part of the training program for engineering students at CentraleSupélec.
Detail any existing community infrastructure, including:
ReLife is hosted under the Github organization of RTE France.
Its documentation is built with Sphinx and the PyData Sphinx theme.
ReLife has no communication channels nor social media accounts.
Are there any specific infrastructure needs or requests outside of what is provided normally by LF Energy ? If so please detail them.
ReLife can be used on any system with Python 3.11+ installed.
Why would this be a good candidate for inclusion in LF Energy?
Large-scale infrastructure investment decisions is a critical problem in the energy industry in the context of climate
change, global supply chain tensions and tight budgets. To our knowledge, ReLife is the only open source software that
implements a complete toolbox to guide decision-making in asset management through the following workflow:
ReLife helps utilities improve the performance of their infrastructure by reducing risks and optimizing investments.
How would this benefit from inclusion in LF Energy?
ReLife's inclusion into LF Energy would allow it to detach its name from RTE and help with its adoption in various
industries. For example, as far as we know, several companies have shown interest in using ReLife for their asset
management needs. The lack of an open, neutral "container" such as LF Energy might be a key element in the limited
adoption of ReLife outside of RTE. We hope that the inclusion in LF Energy will leverage worldwide collaborations on
these topics, including vendors and other asset management organizations, in order to spread the software usage,
consolidate the codebase and add new functionalities.
By joining the LF Energy this project would also benefit from LF Energy's experience in managing open-source communities
and more rigorous project management.
Provide a statement on alignment with the mission in the LF Energy charter.
ReLife aims at providing an open source ecosystem to:
which aligns with LFE mission " LF Energy projects provide a unified approach to developing non-differentiating code
that can enable the world’s power systems to transform rapidly to electrification. LF Energy provides a neutral
leveraged development environment that can accelerate the pace of innovation and target investments in a coordinated and
efficient manner. ".
What specific need does this project address?
This project allows infrastructure manager rationalize their investment decisions to improve grid performance by
optimizing maintenance policies.
Describe how this project impacts the energy industry.
Reliability, a subfield of probability theory that studies the failure of systems, has been well documented for more
than 60 years. However, it is not widespread among utility engineers and it has been frequently obscured by rules of
thumb and black-box proprietary softwares. This can lead to poor decision-making and potentially catastrophic
consequences, as illustrated by Pacific Gas and Electric Company’s involvement in devastating wildfires linked to
inadequate asset management decisions. ReLife brings reliability into the asset management practices to reduce risks and
optimize socio-economical value.
Describe how this project intersects with other LF Energy projects/working groups/special interest groups.
To our knowledge, there are no similar LF Energy projects/working groups/special interest groups. We think that the
inclusion of ReLife to the LF Energy can motivate the creation of an special interest group focused on asset management.
Who are the potential benefactors of this project?
What other organizations in the world should be interested in this project?
Plan for growing in maturity if accepted within LF Energy
Project license
The project is currently licensed under the Apache 2.0 License.
Is the project's code available now? If so provide a link to the code location.
The project's code is available at https://github.com/rte-france/relife.
Does this project have ongoing public (or private) technical meetings?
Currently, there are no public meetings. Private technical meetings are regularly organized at RTE to discuss codebase improvements.
Does this project's community venues have a code of conduct? If so, please provide a link to it?
We don't have a code of conduct yet.
Describe the project's leadership team and decision-making process.
ReLife's leadership team is both composed of mathematicians and engineers. The development follows these steps:
codebase using Pyright and MyPy. This process allows us to refactor the code to adhere to the highest software design standards. Additionally, we write unit tests to prevent regression.
Does this project have public governance (more than just one organization)?
This project has no public governance.
Does this project have a development schedule and/or release schedule?
ReLife has no clear development schedule and/or release schedule.
Does this project have dependencies on other open source projects? Which ones?
ReLife is written in Python. In a near future, it is possible that we incorporate Cython code to bind computations to C
code.
To run it on a computer, users need to install python3 (version 3.11 or greater). The following dependencies are
automatically installed:
Describe the project's documentation.
The document is composed of the following parts:
Each part of the documentation may evolve in the future.
Describe any trademarks associated with the project.
There are no current trademarks associated with the project.
Do you have a project roadmap? If so please attach or provide a link.
We don't have a public project roadmap.
Are this project's roadmap and meeting minutes public posted?
We do not publish a project roadmap nor organize meeting minutes publically.
Does this project have a legal entity and/or registered trademarks?
This project has no legal entity and registered trademarks. However, if possible, we do want to keep the project under
the name of "ReLife" (reliability + lifetime).
Has this project been announced or promoted in any press?
ReLife has been promoted at :
Does this project compete with other open source projects or commercial products?
Not to our knowledge.