The eighty-seventh UQSay seminar on UQ, DACE and related topics will take place online on Thursday afternoon, September 18, 2025.
2–3 PM — Pamphile Roy (LUT Business School, LUT University - Consulting Manao GmbH, Austria)
A novel way of visualizing causal uncertainty
Global sensitivity analysis (GSA) is crucial for understanding model behavior and informing decision-making. However, its adoption is hindered by methodological complexity, implementation challenges, and high computational costs. To address these issues, we developed Simulation Decomposition (SimDec), a hybrid approach that simplifies GSA through efficient computation of variance-based sensitivity indices and intelligent visualization techniques. SimDec is made accessible to practitioners of any background via a no-code web dashboard. The latest enhancement to the SimDec dashboard includes two-output graphs, which allow users to visualize relationships between two model outputs alongside their marginal distributions. This feature is demonstrated through a case study on optimizing a heat exchanger in a nuclear reactor, examining the relationship between the levelized cost of heat and mechanical design characteristics. By providing an intuitive, no-code interface, SimDec democratizes GSA, making it accessible to users with limited mathematical training. This work was presented at the SAMO 2025 conference, highlighting the potential of SimDec to transform how sensitivity analysis is conducted across various fields.
References:
- Uncovering heterogeneous effects in computational models for sustainable decision-making, Environmental Modelling & Software 2024
- Simulation Decomposition in Python, Journal of Open Source Software 2024 - [SimDec dashboard]
- Simple binning algorithm and SimDec visualization for comprehensive sensitivity analysis of complex computational models, Journal of Environmental Informatics Letters 2025
Joint work with Mariia Kozlova (LUT University) & Andrea Saltelli (UPF Barcelona School of Management) & Julian Scott Yeomans (York University).
Organizing committee: Pierre Barbillon (MIA-Paris), Julien Bect (L2S), Nicolas Bousquet (EDF R&D), Vincent Chabridon (EDF R&D), Amélie Fau (LMPS), Filippo Gatti (LMPS), Clément Gauchy (CEA), Bertrand Iooss (EDF R&D), Alexandre Janon (LMO), Sidonie Lefebvre (ONERA), Didier Lucor (LISN), Sébastien Petit (LNE), Emmanuel Vazquez (L2S), Xujia Zhu (L2S).
Coordinators: Sidonie Lefebvre (ONERA) & Xujia Zhu (L2S)
Practical details: the seminar will be held online using Microsoft Teams.
If you want to attend this seminar (or any of the forthcoming online UQSay seminars), and if you do not already have access to the UQSay group on Teams, simply send an email and you will be invited. Please specify which email address the invitation must be sent to (this has to be the address associated with your Teams account).
You will find the link to the seminar on the "General" UQSay channel on Teams, approximately 15 minutes before the beginning.
The technical side of things: you can use Teams either directly from your web browser or using the "fat client", which is available for most platforms (Windows, Linux, Mac, Android & iOS). We strongly recommend the latter option whenever possible. Please give it a try before the seminar to anticipate potential problems.
