Legacy-Modernization: Old software fit for the future

Legacy-Modernization: Making old software fit for the future

Short: In many companies they slumber in secret: Legacy systems.

In many companies they slumber in secret: Legacy systems.

Software that has grown for years and is often written in outdated technologies, which is still working, but is becoming increasingly a brake pad for innovation and growth.

Maintenance is expensive, scalability limited and integration with modern applications a nightmare. But a complete new development is often too risky and too expensive. The solution? A step-by-step Legacy modemization.

This article shows strategies and best practices how to safely lead your old systems to the future.

What are legacy systems and why are they a problem?

Short: Legacy systems are outdated software applications, technologies or programming languages, which are still crucial for a company.

Legacy systems are outdated software applications, technologies or programming languages, which are still crucial for a company.

They have often grown for decades, poorly documented and based on technologies for which there are hardly any experts. The problems are manifold:

• **High maintenance costs:**The maintenance and adaptation of old systems binds enormous resources.

• Reducing flexibility: New functions can only be implemented slowly and with high effort.

• Integration problems: Connection to modern cloud services or mobile apps is often impossible.

• **Safety risks:**Old platforms often do not receive security updates.

• Fachkraft Lack: It is becoming more and more difficult to find developers with COBOL, Delphi or old Java versions.

The risks of doing nothing

Short: Ignoring legacy systems is like driving a car without maintenance.

Ignoring legacy systems is like driving a car without maintenance. Early or later it comes to a standstill.

Companies that do not modernize risk losing their competitiveness, high operating costs and in the worst case a complete system failure.

Strategies for Legacy Moderation: The 7 Rs

Short: There is not one way to modernise.

There is not one way to modernise. Depending on the system and business objective, different strategies are considered which are often summarized as the "7 Rs of Migration":

Strategy Description

**Retire The application is switched off because it is no longer required.

Retain (cont'd) The application will continue to operate unchanged (often only one transition solution).

Rehost (Lift & Shift) The application is moved to a modern infrastructure (e.g. cloud) without any changes.

*Replatform * The application is migrated to a new platform with minor adjustments.

**Replacement ** The application is replaced by a standard software (SaaS).

Refactor (restructure) The code is internally restructured and improved without changing the external functionality.

Rebuild/Replace (New Development) The application is redeveloped from scratch.

The modernization process in practice

Success

References and further reading

Short: The following independent references complement the topics in this article:

The following independent references complement the topics in this article:

• Bitkom – German digital industry association
• German Federal Office for Information Security (BSI)
• European Commission – Digital strategy
• MDN Web Docs (Mozilla)
• W3C – World Wide Web Consortium

"Cloud-native only pays off when operations, security, and cost model match the architecture—otherwise you ship complexity faster."

— Björn Groenewold, Managing Director, Groenewold IT Solutions