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A Comprehensive Guide to Mainframe Modernisation

Today, agility and efficiency are not just desirable; they are the driving forces behind business success. Hence, many organisations face the imperative of modernising their core IT infrastructure. This is particularly true for those utilising mainframe systems, which often handle critical business functions with unmatched reliability and security. 

Mainframe modernisation is not just a trend but a strategic move that can redefine the competitive advantage of organisations across industries. It generally involves updating or replacing legacy software and hardware with newer, more efficient technologies. Let’s explore the dimensions of mainframe modernisation, examining why it’s important, what it entails, and how to do it effectively. By embracing this change, organisations can unlock new efficiency, agility, and competitiveness levels. 

1. What is Mainframe Modernisation? 

Mainframes have been the backbone of enterprise computing for decades, powering critical sectors such as banking, government, insurance, and more. These systems are renowned for their robust performance, superior data handling, and high security. However, the IT landscape is evolving at a rapid pace. Shifts towards cloud computing, big data analytics, and real-time processing are demanding more flexibility than traditional mainframes can typically provide. This poses a challenge for organisations, but one that can be overcome with the right strategies and approaches to modernisation.  

Modernising or migrating these legacy systems is a key solution to these challenges.  

The process of modernisation typically follows one or several of these strategies: 

Rehost The application software can now be provided on a different hardware environment – mostly x86-based – or in the cloud. The applications still function in the same way as they did on the original mainframe. This approach provides cost savings and forms a platform for further modernisation and innovation. 
Rearchitect  Significant changes are made to the application’s architecture, such as splitting it into smaller, more modular components. This approach can make the application more flexible and easier to maintain. 
Refactor  By restructuring the code, the application software retains its existing functionality while reducing complexity and eliminating known weaknesses. 
Rewrite Critical applications are partially or wholly rewritten to be hosted on a modern system platform or in the cloud. 
Rebuild  The application software is rebuilt from scratch and transferred to the cloud. 
Replace  The existing application is usually replaced by standard software available on the market.  
Retire  The legacy application is eliminated as other applications have taken over the business processes.  

The seven Rs of application modernisation. Gartner® originally defined the legendary “Five Rs,” which have evolved to the “Seven Rs.” 

Through these strategies, organisations can transform their traditional mainframe systems into dynamic assets that support current and future business needs, driving growth and innovation across the enterprise.  

Today, businesses often explore combining several strategies to optimise their transition from legacy systems. This approach aligns with the preferences of surveyed IT leaders, as highlighted in this ISG thought leadership paper (2024). Many respondents favour a hybrid strategy that utilises both “Rehost” and “Refactor” methodologies to balance immediate operational needs with longer-term architectural improvements. This combined approach allows organisations to quickly realise cost savings and risk reductions while incrementally introducing changes that enhance system flexibility and maintainability. For example, a substantial 56% of the surveyed leaders opted for rehosting as an initial step to cloud migration, which involves moving applications with minimal changes. This method is often followed by refactoring, where the code is optimised and modernised without altering the application’s external behaviour, supporting a smoother transition, and reducing the impact on day-to-day business operations. Such strategies underscore the preference for phased and thoughtful modernisation that addresses both immediate business needs and future technological advancements. 

2. Key Aspects of Mainframe Modernisation 

2.1 Technology Update 

Hardware and Operating Systems: This includes upgrading to newer mainframe hardware or migrating to completely different platforms, such as cloud environments. 

Software and Applications: Modernising the applications that run on these mainframes, often involving rehosting, re-platforming, refactoring, or replacing them with newer versions or completely different software solutions. 

2.2 Integration and Optimisation 

    • System Optimisation: Enhancing the performance and efficiency of legacy applications by optimising and integrating existing systems and processes, often using modern tools and programming languages. 

2.3 Strategic Business Alignment 

    • Governance: Structured oversight and clear responsibilities are essential to ensure success and alignment with business objectives. 

2.4 Cultural Shift: 

    • Address resistance to change: Failure in transformation projects is unfortunately often due to human factors rather than technical issues. 

    • Tailored strategies: Implement change management strategies that consider the unique cultural and operational dynamics of each organization. 

    • Adopting agile practices: Implementing agile methodologies and DevOps practices to enhance the flexibility and responsiveness of development teams. 

    • The pervasiveness of skills: Addressing the skills gap in mainframe operations by enabling open systems teams to manage the application environment. 

3. Benefits of Mainframe Modernisation 

As outlined in an LzLabs Whitepaper from 2023, mainframe modernisation benefits organisations, helping them stay competitive in a fast-evolving technological landscape. Mainframes were the backbone of many industries for decades. However, as time progressed, changes have become necessary. So here are the key advantages of updating these critical systems:   

    • Enhanced Flexibility and Scalability  

Modernising mainframes can significantly enhance the flexibility of IT infrastructure. By adopting more current technologies like cloud computing and service-oriented architectures, companies can scale operations up or down with greater ease.  

    • Cost Efficiency  

Running and maintaining old mainframes can be costly, not just in terms of direct expenses like energy consumption and parts but also regarding the opportunity costs of not harnessing newer technologies. Modernisation can reduce these costs dramatically.  

    • Improved Integration Capabilities  

As businesses adopt modern applications and data systems, integrating these with mainframe application and data becomes increasingly cumbersome. Modernisation allows for better compatibility between new and existing systems, facilitating seamless integration.  

    • Faster Time to Market  

New technologies embedded within modernised frameworks can expedite development processes and improve operational agility. DevOps practices, for instance, can be implemented more effectively in a modernised environment, leading to faster development cycles and quicker time to market. 

    • Risk Mitigation  

Older mainframe systems often pose risks due to potential failures and the decreasing availability of skilled technicians familiar with their operation. By modernising these systems, companies mitigate these risks, transitioning to more commonly used technologies with a larger pool of expert operators and improved support options.  

    • Aligned Security Policies  

Security is a paramount concern for any organisation, and mainframe systems, while considered very secure, are no exception. Modernisation often includes updates to and alignment with state-of-the-art security protocols, helping protect sensitive data against evolving threats.  

4. Understanding Legacy Systems 

Legacy systems refer to aging computing software or hardware that organisations continue to use despite the availability of newer technology alternatives. These systems are generally retained for their critical role in daily operations and the complexity of updating or replacing them. 

Old mainframe systems pose several challenges and limitations

    • High Operational Costs 

    • Inflexibility 

    • Integration  

    • Scalability or Capping 

5. Choosing the right modernisation strategy 

Selecting an appropriate modernisation strategy for mainframe systems requires a careful and strategic approach; these are the key points you should consider: 

    1. Assessment of Current Systems 

    1. Alignment with Business Goals 

    1. Technology Selection 

    1. Risk Management 

A structured approach helps organisations navigate the complexities of choosing a modernisation strategy that best fits their needs without unnecessary disruptions. 

6. Modernisation Approaches by Cloud Platform  

Explore the forefront of mainframe modernisation with specific strategies tailored to the leading platforms in the technology industry. Each platform offers unique tools and services designed to transition your legacy systems into the future seamlessly: 

6.1 Azure Mainframe Modernisation 

Microsoft Azure’s mainframe modernisation capabilities focus on seamlessly transitioning legacy systems to the cloud. Utilising tools like Azure Migrate for detailed assessment and migration strategies, it also integrates Azure’s cloud services for better flexibility and scalability. Additional features include continuous security updates and advanced analytics to optimise system performance and cost-effectiveness. 

6.2 AWS Mainframe Modernisation 

AWS provides a holistic approach to mainframe modernisation through services like AWS Migration Hub, simplifying transition planning, and AWS Managed Services for ongoing system management. Their strategy emphasises scalability and cost reduction, leveraging AWS’s cloud infrastructure to enhance system performance and reliability. 

6.3. Google Cloud Platform (GCP) Modernisation  

Google Cloud’s Mainframe Modernisation supports the migration of legacy systems to the cloud, supporting languages like COBOL and CICS. The strategy offers tools and services for cost reduction, agility, and innovation through integration with advanced cloud services. Expert support will ensure a secure and smooth modernisation process. 

7. Mainframe Migration Products and Services 

At LzLabs, we provide comprehensive services and software designed to migrate mainframe systems step-by-step with minimal disruption. At the core of these offerings is the LzLabs Software Defined Mainframe® (SDM), which facilitates the seamless transition of legacy applications to modern cloud-based platforms without the necessity for recompiling code or altering existing applications. 

This innovative approach simplifies the migration process and ensures that the robustness and reliability of legacy applications and data are maintained in a new, scalable, and secure environment, including seamless integration with remaining legacy systems and modern open systems.  

8. Case Studies and Use Cases 

Real-world examples of successful mainframe modernisation initiatives provide valuable insights into the benefits and challenges of modernising legacy systems. 

Swisscom, a leading telecommunications provider, is one such compelling case study. In partnership with LzLabs, using the Software Defined Mainframe (SDM) solution, Swisscom successfully left its mainframe systems behind. Through this collaboration, they achieved significant cost savings and improved agility and scalability while maintaining the reliability and security of their legacy systems.  

“It works. It really works. You need to have the courage, and you have to face a change project, but it works. Go for it” 

Markus Tschumper, Head of General IT Services, Swisscom 

Further examples from industries like Automotive, Banking, Insurance, and Telecommunications underscore the effectiveness of LzLabs’ approach to mainframe modernisation and highlight the tangible benefits organisations can achieve by embracing innovative solutions for legacy system transformation. 

Read more about the importance of partnering with your systems integrator and mainframe modernisation solutions provider in this article by LzLabs CEO, Thilo Rockmann. 

Please also explore further use cases e.g. for step-by-step refactoring, DevOps and process automation, legacy-to-standard-software migration and reducing cost for audit compliance.  

9. Future Trends in Mainframe Modernisation 

As technology continues to evolve, future trends in mainframe modernisation are poised to transform the landscape of IT infrastructure. One such trend is the integration of generative AI to enhance mainframe applications. By leveraging generative AI, organisations can streamline the modernisation process and accelerate the development of new features and functionalities for their mainframe applications. This technology enables developers to quickly prototype, iterate, and refine code, leading to faster deployment cycles and improved time-to-market for innovative solutions.  

With its innovative approach to mainframe modernisation, LzLabs is at the forefront of integrating cutting-edge technologies like generative AI into legacy systems, empowering businesses to future-proof their mainframe applications and drive innovation in an increasingly competitive market landscape. 

10. Selected Whitepapers and Reports 

Unlocking the Future with Mainframe Modernisation: An ISG Thought Leadership Paper (2024, English) 

ISG Sweet Spot Report: LzLabs (2024, English) 

CIO Magazine: Mainframe Modernisation (2024, English) 

CIO Magazin: Mainframe-Modernisierung (2024, Deutsch) 

Is the Mainframe Your Innovation Platform? (2023, English) 

Livre Blanc : Le mainframe est-il VOTRE plateforme d’innovation ? (2023, French) 

Mainframe Modernization | Latest Survey Results (2021, English) 

The Benefits of Moving Mainframe Applications to Microsoft Azure (2020, English)