Result
Legacy Integration
How do you support legacy systems into retirement?
Digital transformation requires modern, secure and adaptable IT landscapes. This is in line with a survey conducted by Statista in 2019, in which 38% of the companies surveyed rated the modernization of legacy systems as a priority.1 The reason for this is that legacy systems can lead to significant problems. For example, outdated IT systems can slow down a company's growth and cause unnecessary costs. A full 83% of companies surveyed in Germany cite outdated technology and technical debt as a significant cost factor2,3, yet 58% of companies still have no process for managing technical debt.4
What is a legacy system?
A legacy system (also known as a legacy system or legacy application) is an outdated or older computer or IT system that has generally been in use for many years and no longer meets current technological standards and requirements.
How legacy software develops
Software becomes obsolete when it reaches the so-called “obsolescence point” (see graphic). It then no longer corresponds to the state of the art, becomes increasingly expensive, less efficient and more prone to failure. At this point at the latest, you should start looking at how you can replace or modernize the application.
Legacy Management Framework
The Legacy Integration workstream team has taken up this challenge and looks at the causes, emergence, risks and effects of legacy systems on a company and describes a specially developed framework for the identification, integration, replacement and governance of such systems.
Identification
In the identification step, the legacy systems are recognized, listed and evaluated in a 360° view using a previously defined list of criteria. All visible but also non-transparent potential costs are taken into account. Finally, the framework helps to prioritize the systems according to their importance for the company and communicate them to management in order to decide whether to continue operating them or replace them.
Continued operation/integration
Continued operation requires the integration of the legacy system into a modern IT landscape. The necessary steps and considerations were documented and can be found in the detailed results. The workstream team recommends a modular integration architecture approach that allows the legacy system to be operated for a limited period of time and thus replaced at any time without having to adapt the existing systems.
Replacement
The replacement of a legacy application must be timed carefully. If it is done too early, the successor technology may not yet be fully developed. If it is too late, operating risks and costs have already increased. The framework also addresses the prerequisites and types and methods of replacing a legacy application.
Governance
By anchoring legacy query criteria in a company's enterprise architecture governance, legacy management can be integrated into day-to-day work. Various tools are presented, including how architecture principles can help to avoid new legacy systems.
Best Practices
In addition to the architectural principles from a conceptual perspective, the team provides best practices as practical solutions for the integration of legacy systems.
Conclusion of the workstream
The results of the workstream were clearly presented and summarized in a playbook. It offers enterprise architects valuable assistance in identifying, integrating and replacing legacy systems. Best practices, argumentation aids and exemplary integration patterns supplement and clarify the theoretical considerations. The difficult topic of IT/OT integration is also taken into account. Legacy integration will continue to play an important role in EAM in the future, as all software becomes a legacy system at some point.
Sources:1Statista 2019;2LeanIX (2023);3Insight Direct USA (2023);4Stepsize (2021)