How Saint-Gobain Uses Celonis to Save 240 Weeks per Year on Internal Audits

Saint-Gobain has been manufacturing materials since 1665, when King Louis XIV of France founded the company to produce mirrors for the Palace of Versailles. Over three and a half centuries, it became a global giant: 170,000 employees, operations across 75 countries, and more than €40 billion in annual sales. Running internal audit at that scale means conducting around 120 missions per year, each investigating compliance, conformance, and risk exposure across operations that span the geopolitical and commercial spectrum. Hubert Reichardt, VP of Audit, Risks and Internal Control, is responsible for every one of them.

Before Celonis, each audit mission lasted one to two months. A team of six or seven central auditors would arrive at an entity, spend five to seven weeks on site, and attempt to reconstruct the reality of purchasing and selling processes from the paper documentation available. Audited teams resented the intrusion. “People felt a little bit overwhelmed,” Reichardt explained. “They saw a team of seven, six people coming from central audit, staying five, six, seven weeks, and they were complaining that it was quite disturbing for their business.” Beyond the disruption, the process itself was inherently limited: auditors could only see what was documented, not what was actually happening in the ERP systems.

Connecting Celonis to the ERPs of audited entities changed the information available to Reichardt’s team overnight. Process maps generated from real transaction data revealed the actual flow of purchasing and selling activity — what Celonis calls “spaghetti maps” — exposing deviations, bottlenecks, and irregularities that paper documentation had never surfaced. The effect on audited teams was immediate. “After seeing the map and the data, they were obliged to recognize the reality,” Reichardt said. “The teams were amazed.” For auditors, the advantages were twofold: exhaustivity, meaning the system examined every transaction rather than a sample, and objectivity, meaning findings were grounded in system data rather than human reconstruction.

The operational impact was substantial. With Celonis providing data-driven starting points for each audit, the overall mission length dropped by one to two weeks per engagement. Across 120 missions annually, that adds up to 240 weeks saved — or roughly six full-time employee equivalents freed from audit preparation and manual investigation. Reichardt noted a further consequence: when a plant manager sees a data-backed report showing that late supplier payments cost the entity €50,000 in the prior year, the conversation changes. “This speaks to him,” he said.

The shift in perception has been as significant as the efficiency gain. Internal audit, long seen within Saint-Gobain as a “policeman” function, is now understood as a business partner — one that arrives with evidence rather than interrogation. Reichardt sees this reframing as foundational to the program’s future: “We have to show real numbers, real figures, and real progress, and this is what will happen.” Saint-Gobain is now evaluating expanded use of the Celonis Execution Management System for continuous process improvement and cost identification across its global manufacturing estate.