Auchan Retail
Auchan uses a Gemini assistant to rewrite the most complex flows of its logistics middleware in three months
Auchan, a French retailer, built an assistant on Google's Gemini to explain a poorly documented in-house logistics system to its developers. Its IT chief says the most complex flows, about 30% of the system, were rewritten in three months instead of a year.
Key figures
Copied exactly from the sources. Copy any figure with its citation.
3
months, against one year without generative AI
Time to rewrite the most complex flows, about 30% of the middleware, versus the IT chief's estimate without generative AI1
The problem
Auchan relied on an in-house middleware, the software that links supplier and warehouse logistics with store logistics. Its IT and data chief describes it as complicated, poorly built and poorly documented, because it mixed technical flow rules with business rules. To replace it, developers first had to work out what the code did, a step called reverse engineering that normally takes 30 to 40% of the time in a migration to a newer system.
What they built
Auchan built an assistant that answers developers' questions about the old application. It is based on the middleware code and the little documentation that existed, spread across Word files, Excel files and comments inside the program. The assistant explains how a given flow works and which data format it uses. It also describes the logistics workflows running in the background and what a change to one workflow would affect elsewhere in the code.
How they did it
The assistant runs on Google's cloud and uses Google's Gemini model. Developers asked it questions instead of analysing and testing the code by hand. Auchan used it to rewrite the most complex flows, about 30% of the middleware, which went live in the course of the summer, per the article of October 2024. The project needed three months of implementation. The article does not give a team size or a cost.
Results
Auchan's IT chief says the work took three months, against about a year without generative AI, because the assistant removed the slow reverse-engineering phase. The article adds that, with Auchan's assistant, that phase now takes 10% to 15% of the work, against the 30 to 40% it generally takes. He says Auchan now uses the technology for every application it rewrites.
The article gives no figures on cost, defects or later phases of the rewrite.
Lessons for your project
Aim AI at the slowest step of a project. Auchan targeted the work of understanding old code, which the article says generally takes 30 to 40% of migration time, rather than the writing of new code.
Build the assistant from what exists. Auchan used the system's code plus scattered Word files, spreadsheets and code comments, so poor documentation was no blocker.
Start with the hardest part. Auchan applied the tool to the most complex flows first and says it now uses the method on every application it rewrites.
Measure effort against a baseline. The article gives the share of time spent on reverse engineering before and after, which makes the gain easy to check.
Caveats
- The three-month and one-year figures and the 30% share are quotes from Auchan's IT and data chief. The 30 to 40% and 10% to 15% shares are stated by the journalist, the first as a general figure for migrations, and not attributed to a named person. The article is in French and no audited data is shown.
- The one-year comparison is Auchan's estimate of what the rewrite would have needed without generative AI, not a measured control.
- The article names Gemini without a version. The article does not date the go-live; it says the rewritten flows were deployed during the summer, so the deployed date shown is the article's month. The year of that summer is implied by the article date, not printed.
- A second article, from LSA, was found but could not be opened, so it is not cited.
- The same article covers other Auchan generative AI projects, such as a call-centre assistant and an HR assistant. This case covers only the middleware project.
Sources
- Chez Auchan, l'IA générative fait gagner du temps à trois métiers
Journal du Net · 2024-10-16 · News · journaldunet.com
Summarized in our own words from the sources above. Spotted an error? See corrections.