A mainframe time bomb? How companies seamlessly manage legacy integration

Published May 17, 2024

  • Core-Business Software Development

A shortage of skilled workers – the German labor market, challenged by severe demographic change, has been sounding the alarm for years. While employees can often choose their jobs, wages are rising and additional benefits such as working from home, workation and company pension schemes are becoming increasingly important, companies are desperately looking for the right specialist staff. The situation in IT departments is particularly precarious: 70 percent of German companies complain about a lack of qualified employees, while only two percent consider the supply to be sufficient. All told, Germany as a business location currently has some 150,000 vacancies in the IT sector. This, in a nutshell, is the situation in which the mainframe systems of many companies find themselves during the transformation phase: Software, operating systems and programming languages are reaching the end of their life cycles as they are no longer compatible with modern web applications. An acute shortage of specialist staff impacts far-reaching change processes at the heart of corporate IT, posing major challenges for many companies. How might they best deal with them?

As the central architecture, mainframe systems, including the associated software components, are at the very core of many corporate IT systems. As a robust workhorse, they have been indispensable for many companies for decades. Mainframes are used to manage huge amounts of data, handle large transaction volumes and provide critical applications. This primarily includes online transactions in real time, such as checking account balances and processing orders in an e-commerce system. In addition, there is so-called batch processing – the processing of similar tasks in batches. Mainframes have performed efficiently and reliably for many years, running smoothly in key business areas from the booking system to accounting. However, although some of them have interfaces to the “modern” world, many of the solutions used are based on in-house developments. They were programmed long ago and continuously adapted to meet special requirements.

End of the life cycle

Despite the reliability of their functions, many mainframe solutions have now reached their limits. Applications based on programming languages such as Cobol, PL/I and Assembler are often at the end of their life cycle. This causes problems such as limited adaptability, complex maintenance, inadequate documentation and incompatibility with modern web and mobile solutions. To make matters worse, many of the experienced developers and specialists who are familiar with mainframe technologies are now reaching retirement age. The problem is exacerbated by the lack of young talent willing to familiarize themselves with outdated programming languages such as Cobol and work in this environment. While costs and high personnel costs used to be the biggest challenges for companies, incompatibility and the lack of specialists are now the greatest stumbling blocks.

The transformation of mainframe solutions is certainly a complex task: Modern programming languages such as Java or Python must be implemented while existing applications must continue to be operated in parallel. Meanwhile, the transformation itself requires a great number of qualified developers that are nowhere in sight.

In an increasingly dynamic labor market that is particularly lacking in IT specialists, young talents no longer want to deal with these old, bulky systems. Yet, there’s simply no alternative to modernizing mainframe systems for most companies today.

Bernhard Davignon, Partner in the Technology & Innovation Division at Wavestone

Is there no alternative to the public cloud?

Many large corporations have therefore been consistently migrating their systems to the public cloud for several years: The three dominant US hyperscalers Amazon, Google and Microsoft dominate the market for web services that are completely outsourced to the servers of these service providers. This provides customers with high scalability and powerful tools – but it also creates dependency on the presumptuous cloud providers. “And at least the feeling of a certain loss of control,” says Bernhard Davignon. “In addition, there are complex federal and EU requirements ranging from consumer protection to data security, such as the Cloud Act and the General Data Protection Regulation (GDPR),” says Davignon. “Thus, small and medium-sized companies often shy away from a comprehensive cloud migration.”

Yet another consideration: Above all, smaller companies fear that the large providers will not cater to their needs in as much detail as global corporations do. What if basic tools and services are discontinued without replacement after a while or a detrimental change has been made to the license terms? “There is no alternative to migrating to the public cloud,” says Davignon. “Companies have the choice of modernizing their mainframe systems on-premise or migrating to the private cloud. Both are real alternatives for which there are strong partners with sufficient expertise and manpower.”

Three approaches

A successful transformation requires not only technical measures, but also careful planning and implementation of project management, change management and personnel planning. There are three ways to do this.

This approach involves updating the mainframe applications and systems while they continue to be operated locally in the corporate environment. The conversion from older programming languages such as Cobol to more modern languages such as Java helps to improve maintenance requirements, scalability and flexibility of the systems.

“Whether on-premise, public or private cloud: There is no silver bullet when it comes to legacy integration of mainframe systems,” says Davignon. “Depending not only on the size and manpower of a company but also on its business area, customer base and services, an individual, tailor-made solution should always be developed.” This can consist of one of the three paths, but also of a partial or multi-cloud strategy.

The first step is to take stock with a competent and trustworthy partner: Which IT applications does the company need? Which ones already exist, which ones need to be added, and which ones may be superfluous? Where does the company want to develop in the medium term – and what migration strategy does this require? The partners develop a target image on this basis. Migration then takes place to either a public or a private cloud. Continued operation on-premise is also possible after modernization if desired. At the end of the process, decommissioning means decommissioning outdated systems and applications.

The five R’s

When transforming and modernizing legacy systems on the mainframe, it is essential not only to migrate them in line with the business and requirements, but also to continue operating the original systems. Proven strategies for efficient and secure modernization and migration can be found in the “5 Rs”:

Applications that are no longer required are shut down. To do this, the affected functionalities and systems must first be isolated. This reduces ongoing operating and maintenance costs.

All R components and future strategies, whether on-premise or in the cloud, require strong project and change management. This is the only way to ensure the continued operation of the old systems and the transition to the new ones runs smoothly and without the risk of system failures and downtimes. The basis for this is good, future-oriented personnel planning and professional support from competent partners who can also provide managed services solutions if required.

Ensuring competitiveness

The modernization of mainframe systems is crucial for the future viability, reliability, security, scalability and cost efficiency of companies’ IT landscapes. The integration of new technologies and adaptation to changing business requirements require continuous further development and modernization of in-house systems. The current public cloud trend is often the right way forward for corporations with tens of thousands of employees – but this does not necessarily apply to every company. For medium-sized companies in particular, it is important to analyze precisely and initiate change processes strategically and wisely. In addition to investing in the transformation of legacy systems, companies should also shape their HR policy with an eye to the future and trust strong partners. This strengthens their competitiveness and ensures long-term success.


  • Bernhard Davignon

    Partner – Germany, Munich