Why Modernising Gen Legacy Systems Is No Longer Optional

For decades, Gen applications have quietly powered some of the world’s most critical business processes. Originally designed in the heyday of information engineering, these systems became the backbone of industries like financial services, insurance, and government. Reliable, scalable, and capable of processing enormous transactional volumes, Gen has been the unsung workhorse of enterprise IT. 

But today, continuing to rely on Gen carries significant risks, risks that every CIO and CTO must face head-on. These insights come from Mark Hankin (TXP’s Application Modernisation Partner), a Gen transformation expert with over 30 years of experience in application transformation, and 13 years specialising in Gen systems. 

The Hidden Risks of Staying on Gen

1. Retiring Resource

Most Gen systems were built and maintained by specialist teams over the past 20–30 years. As these systems continue to age, organisations face a shrinking pool of experienced resources with the deep domain knowledge required to maintain and adapt them. As Mark highlights, this gap between demand and available expertise makes it harder for businesses to respond quickly to changing market conditions. In short: agility slows while competitors move ahead. 

2. Escalating licence costs

A further risk comes from the steady rise in licence fees associated with running Gen applications. Many organisations are seeing significant annual increases, which in some cases reach unsustainable levels and place real pressure on operating budgets. Left unchecked, these costs can threaten the long-term viability of critical business systems. 

3. Architectural isolation

Gen applications, though robust, are often highly isolated. While that can be positive from a cybersecurity perspective, it makes integration and extensibility far more difficult. As digital ecosystems grow more interconnected, this lack of flexibility becomes a significant barrier to innovation. 

Upgrade or Modernise? Understanding the Choices

When organisations consider their options, the debate often centres on “upgrading” versus “modernising.” 

Upgrading usually refers to moving to a newer version of Gen or changing infrastructure components (such as the database). This can bring incremental improvements, but it does little to address the structural risks outlined above. 

Modernisation means going beyond surface upgrades. As Mark explains, it can involve migrating Gen applications into new, maintainable languages like Java, .NET, or COBOL, often opening the door to cloud adoption. It can also mean Functional Area Isolation, using TXP’s globally unique automation to break up monolithic Gen applications into modules aligned with business functions. This enables phased transformation, spreading cost and risk while allowing the business to prioritise areas of greatest value. 

The most effective transformations are usually phased and carefully measured, balancing technical ambition with business continuity. 

Discovery: Reducing Risk Before You Transform

Gen transformations are often described as “the biggest can that’s been kicked down the road” for decades. They are postponed precisely because they feel risky, after all, these are core systems like tax platforms, banking engines, and claims management systems. 

That’s why discovery is critical. 

 Mark and the TXP team use an advanced migration toolset (Metatech Migration Works from TXP), developed over 20 years, to interrogate the Gen meta model in extraordinary detail. This enables them to: 

• Analyse millions of objects across large estates. 

• Identify redundancies (often 20%+ of code is unused). 

• Map dependencies and complexities. 

• Create a clear line of sight from current state to desired future state. 

Their discovery phase typically lasts 4–12 weeks, depending on estate size, and often includes a proof of concept to build confidence. The result? Clients know precisely what they’re working with, and what the path forward should look like. 

Breaking the Myths About Gen Transformation

Over years of global transformation projects, Mark has encountered some common misconceptions: 

“It’s not possible.” Many organisations have been burned by generic transformation attempts that failed to account for the unique complexities of Gen. The key is starting from the Gen meta model, not the generated code. Without this foundation, the transformation is likely to fail. 

“It’s easy to modernise and move straight to cloud in one step.” While possible, this is rarely simple. Running parts of an application in the cloud while others remain on a mainframe introduces major latency and architectural challenges. Success requires careful phasing and experience.

Why Experience Matters

Mark and the TXP team have been modernising Gen systems for over 20 years, across industries and continents. Leveraging their proprietary MetaTech tooling, they’ve solved the technical blockers that typically stall transformations. 

Every organisation’s journey is unique. Some need full code transformation. Others prefer phased modular migration. Some want to reduce licensing costs immediately; others want a path to cloud over time. 

Whatever the destination, the important thing is to start the conversation. 

Summary

Gen applications have served enterprises faithfully for decades. But the risks of inaction are growing too large to ignore. With the right strategy, tools, and partner, modernisation is not only possible, it can be transformative. 

As Mark advises, “Every transformation is unique, but with the right approach and experience, the technical blockers that hold most companies back can be overcome.” 

At TXP, we’re here to help you design and deliver a modernisation journey that works for your business. 

If you’re ready to explore your options, get in touch with us. We’ve done this successfully across the globe, and we can help make it a success for you too.