Infrastructure at the touch of a button: Stadtwerke München runs SAP on the Microsoft Cloud to keep Munich supplied with utilities

The challenge: Moving a large on-premises SAP landscape to the cloud

Energy for modern everyday living, heat in the cold months, urban mobility, and a fast internet connection that opens up all the possibilities of digital transformation—SWM lays the foundation for a high quality of life in Munich. SWM has digitalized countless processes and set most of them up in SAP—for example, meter readings for electricity and water billing, which are sent to SAP for processing. “SWM and SAP have a 30-year partnership,” says Mathias Auer, Head of Infrastructure and Platforms at SWM. “Since almost all our divisions work with the system, we need to make sure that this business-critical application is always state of the art and able to adapt and grow quickly and flexibly.” 

That’s why SWM’s IT department wants to bring the entire SAP landscape up to date by moving it into the cloud. “Growing our on-premises infrastructure was no longer an option for us: the associated hardware and maintenance costs are just too high. SWM needed greater scalability, more options, and faster provisioning of instances for the transformation of the various SAP system landscapes,” Auer says. At the time of provisioning, however, it was often not possible to make valid size estimates. All in all, no easy task: “We had a 30-year-old SAP solution that was completely interlinked and based on Oracle databases. A simple lift and shift was essentially impossible. We would’ve had to set up every single system environment, every single system cluster, and every single function from scratch in the cloud and based on HANA databases. That’s why we were looking for a suitable target infrastructure, but especially for a new technological approach for system deployment.” SWM overcame the challenge with Microsoft Azure and infrastructure as code. 

The solution: Efficient and automated SAP rollout in the Microsoft Cloud with infrastructure as code

Even before the migration, SWM was already using Microsoft 365 company-wide, as well as Microsoft Entra ID for identity management. The company has also long relied on Windows as an operating system—especially as a server back end. Consequently, the most compelling argument for Azure was the high level of integration between Microsoft solutions. In addition to the back-end systems, the future hybrid architecture will also include many other cloud services, for example on the BTP. The decades-long collaboration between Microsoft and SAP, which also provides the infrastructure for many BTP services, was another argument in favor of Azure. “This means that despite having different operating models, we’re back on a common infrastructure platform,” Auer says. The SAP operating platform is orchestrated using the ALPACA solution provided by the Public Cloud Group (PCG). The SAP systems were migrated using the familiar SAP Software Update Manager tool; HANA source systems were migrated by means of system replication.

Since the start of the system migration in 2021, seven different SAP landscapes—i.e., different system clusters—have been moved to the cloud. “These are systems and their subsystems that we’ve set up completely from scratch in Azure on the basis of the HANA database, with between 256 GB and 5.7 TB of memory per HANA database,” Auer says. “Our SAP Central User Administration (CUA) and the SAP Business Intelligence (BI) environment are now fully in the cloud. Setting up these two systems completely manually and on-premises would have cost significantly more and taken considerably longer—infrastructure as code in the cloud let us implement this much more quickly and efficiently.”

The great advantage of infrastructure as code is that the infrastructure is initially set up as a blueprint in the form of code, with a precise description of what the infrastructure required to implement a solution should do. Factors such as storage space, computing capacity, or network resources are defined. “We bring the properties of hardware into a code structure and run them automatically in the cloud using the Terraform framework. From that moment on, we have the infrastructure we need for the desired SAP system,” Auer says. “These blueprints can be versioned, duplicated, further developed, or even deleted.” That means SWM has a collection of different infrastructures that it can use when migrating similar SAP systems that it needs for company projects. The more systems that are migrated, the faster and more flexibly they can be used and adapted. “By opting for Azure, we can set up SAP systems in the cloud using infrastructure as code more quickly and efficiently than would ever be possible on-premises,” Mathias Auer says.

Stadtwerke München will benefit from its new expertise in cloud technologies in the future—even beyond the SAP migration, which ends in 2027. “It was definitely a bold step to migrate our largest, most complex, and particularly business-critical application to the Azure cloud,” Auer says. “But it was the right decision—and we learned the ropes very fast, thanks in no small part to Microsoft’s Enterprise Skills Initiative.”