Fast-track Visual Basic (VB) modernisation with Generative AI

If you followed my previous article on the challenges of killing COBOL, you’ll know I’m passionate about modernising legacy technology.

Today, I’m turning my attention to another stalwart of technology; Visual Basic (VB). Like COBOL, VB boasts a remarkable legacy, as evidenced by the fact that across every sector, VB applications are still running critical parts of our customer’s IT estates.

However, times have changed and it now faces many challenges. Let’s explore these difficulties; why VB modernisation has been so demanding and how Generative AI can help.

Why VB modernisation has been so challenging

Easy to say but harder to do – the simple truth is that modernising VB estates has historically been slow, expensive, and high risk.

Differences in system architecture made the modernisation path from VB6 to VB.NET or C# very difficult and large-scale rewrite projects often came with five-year timelines, multi-million-pound budgets, and significant disruption to business operations.

The complexity of legacy systems (combined with limited in-house knowledge) made these programmes daunting to even the most ambitious IT leaders.

Generative AI will unleash modernisation at scale

Generative AI and its genuinely game changing coding abilities has opened the door to an entirely new approach to legacy modernisation.

Previously, we would have relied entirely on deterministic rules-based approaches which produced transformed code that was complex, verbose and difficult to understand, thus limiting their value – a route we would not generally have advised our customers to take.

What we’re seeing emerge now as a standard pattern is the effective combination of these technologies:

• Rules based solutions providing a first pass that does the heavy lifting and code transformation
• With subsequent GenAI iterations to improve readability and maintainability, and to use Agentic AI to iteratively resolve issues found during the transformation process

Indeed, if you look under the hood of some of the key players in the market, take the Copilot upgrade assistant for Java as an example, you will find that it follows the pattern set out above.

63% faster VB modernisation

This isn’t theory — we’ve applied this approach successfully. For one private sector client, initial estimates for modernising their VB estate suggested a five-year programme. Using our framework, we delivered the transformation in just 18 months. That’s a 63% reduction in time and effort — without compromising quality or stability.

Similarly, our work with National Highways to modernise their VB systems earned us the Microsoft Global Modernisation Award in 2023. These successes prove that this isn’t an experiment — it’s a scalable, repeatable approach to transforming complex legacy estates.

The bottom line

Generative AI is reshaping what’s possible in legacy modernisation. By combining automation, AI, deep expertise and proven delivery, it’s now feasible to accelerate VB modernisation by up to 63%, reduce risk, and unlock opportunities for intelligent transformation.

If you are struggling with unsupported Visual Basic applications and you’re ready to explore a faster, lower-risk path to modernisation, take a look at our eBook on ‘Breaking point to breakthrough’ and contact us to take part in our pilot engagement where we can help you accelerate your modernisation and see results in just 5 days.

You can connect with me directly here on LinkedIn, and we’ll walk you through how our approach can help you move beyond legacy and build for the future.