Customer Success Stories
At 3:00 p.m. on a Thursday, employees of the Madrid City Council left their workplaces. The following Monday at 9:00 a.m., they returned to find a completely new system. During that interval, the full migration to SAP S/4HANA was carried out—that is, the migration of the financial system of a large municipal administration. And all of this without a single critical incident.
Published : 10/04/2026
An achievement worthy of the community this public entity serves. With 3.3 million inhabitants, an annual budget of €7 billion, and 30,000 municipal employees, the Spanish capital is one of Europe’s major metropolises. “When I attend international meetings, I always say that Madrid is like a small nation. In terms of complexity, it is comparable to countries such as Estonia or Lithuania,” says Ángel Fernández Bueno, Deputy Director General of Corporate IT Systems at the Madrid City Council (IAM). The city covers many of the functions of a state, such as healthcare, education, taxation, and sanctions.
For example, it processes 2.5 million traffic fines each year. All these critical functions were based on the SAP ERP Central Component (ECC), implemented between 2004 and 2006. However, the coexistence of financial and human resources modules within the same instance had become an obstacle. “It was like a battle every year to decide which would go first and to check whether the other would be affected,” explains the Deputy Director General. Updates to one blocked the evolution of the other.
In 2019, IAM launched an ambitious five-year transformation program. The objective: separate the financial and human resources systems, modernize the database, and then migrate the entire financial component to the new generation of SAP software, S/4HANA. All of this without any service interruption in an administration that operates 24/7.
Inetum, a partner of the City Council since 2004, was entrusted with this mission. The company used the SAP Activate methodology and structured the migration in successive cycles (sandbox, testing, production). More than 90 people participated, coordinated by a project office dedicated to the migration. “Because of how long Inetum has been working with us, they know our environment, our teams, and our internal clients,” emphasizes Ángel Fernández Bueno.
The results speak for themselves: zero critical incidents, a smooth migration for the system’s 4,500 users, and greater interoperability with cross-functional administrative systems, including electronic signatures, legal notifications, and administrative records. The project has been described as a “benchmark in the public sector” by AUSAPE, the Spanish SAP Users Association.
Renewed in June 2025 for four years and a total amount of €13 million, the contract sets a new objective: to migrate the human resources system to S/4HANA before the end of 2026. But the ambition goes beyond technical improvements. According to Fernández Bueno, “this is a contract for innovation, with artificial intelligence, low code, and data.”
