The Risks of Migrating Visual Basic App with Automation Tools

If we had a Visual Basic app to upgrade, we’d never use automation tools. Now, you might be thinking that’s a pretty bold claim! Let’s roll back in history to provide you with an explanation.

Back in 1991, when Visual Basic 1.0 was released by Microsoft, it became popular among enterprises that wanted to build in-house applications. Over time, Visual Basic attracted a large community of developers who loved it as a friendly environment for beginners. In a nutshell, Visual Basic showed us what programming could do.

Now there are thousands of VB apps scattered throughout the world filled with spaghetti code. Why is this? Because newcomers weren’t skilled enough to follow coherent development practices when they were developing systems with Visual Basic. This leaves little hope that automation tools can convert this code to the new platform properly.

Or can they? Let’s find out together.

Spagetti code is technology jargon that refers to code that is written without a coherent structure and rules.

What Is Happening with Visual Basic in 2021: To Migrate or Not to Migrate?

Microsoft no longer supports Visual Basic — its last version was designated as a legacy in 2008 — though it does still provide the community with applicable documentation. Many users are still using WinForms to build business applications in Windows, and a few are building websites using ASP.NET WebForms.

However, with new technologies on the horizon, Visual Basic has become an outsider in the industry; it doesn’t quite fit in. That’s why Microsoft rolled out a VB and C# coevolution strategy to unify the .NET ecosystem and facilitate the transition from legacy VB code. Using C# capabilities, for example, VB apps could be leveraged with the web interface or powered with mobile access. This approach has proven itself many times over.

By the time of the latest .NET Conference, named “Focus on Windows,” it had become clear: Microsoft won’t evolve Visual Basic as a language but will integrate it into the .NET environment. That leaves almost no choice but to migrate to the newest .NET version.

How to Transfer VB to a Web App with Automation Tools

As soon as the need for migration emerged, Microsoft (in collaboration with partners) launched specialized conversion tools transforming VB code to C#, VB.NET, and .NET platforms. The recommended tools include:

  • Microsoft Visual Basic Upgrade Wizard: a tool suitable for small and medium projects. It will partially migrate your code to Visual Basic 2008.
  • Visual Basic Upgrade Companion (VBUC): a more powerful tool to upgrade Visual Basic 6.0 apps to the .NET platform.
  • Code Architects VB Migration Partner: a tool for converting code from VB6 to VB.NET.

In its documentation, Microsoft points out that these tools can’t be an end-to-end solution.

How Do Automation Tools Work?

Transferring VB code with automation tools is a fast and cost-effective way to upgrade legacy software, compared to rewriting from scratch. The migration goes through a number of stages:

As we can see, conversion tools alone leave wide gaps in the migration. In any case, you should assemble a qualified team who’ll handle the rest of the work (about 70%). But, if your project is simple and non-buggy, you needn’t be bothered with the manual work; you may be able to make do with the software only.

Disadvantages of Visual Basic Conversion Tools

As we mentioned previously, conversion tools are imperfect. There are serious disadvantages of automated migration:

Can’t deal with complex projects

Enterprise users who have dozens of VB apps under one roof won’t benefit from conversion software. Even though software providers claim its efficiency for apps with 650K lines of code and more, they have many dependencies that are difficult to structure. As such, the amount of manual work will outweigh the pros of automated migration. From a practical standpoint, it’s not cost-effective in the long run.

Require lots of manual enhancements

Developer communities are plastered with complaints about VB code fixes. For instance, folks from Stack Overflow encountered about 15,000 errors when compiling their code to C#. Sometimes they spend months polishing and debugging the codebase.

Here are a few things that can’t be converted with VB conversion software and require a rewrite:

  • ActiveX Document (COM-based components)
  • Property Page
  • Microsoft Data Report (*.dsr)
  • COM Crystal Report objects
  • ActiveX container

The post-migration stage will also need plenty of architectural, performance, user experience, and security improvements.

Low level of customization for the specific needs

Most of the declared tools target a specific Visual Basic version: VB6, which is called a last release of the “real Visual Basic.” Software providers write off earlier versions. But they still exist and need proper support.

If you migrate the app without thorough preparation, you’ll later face issues related to the business logic. As a result, you won’t be able to take advantage of the new platform.


If you need to migrate VB apps, we advise you to look to custom software development services. This approach can be tricky and complex, but you get predictable outcomes.

Migration with automation tools creates gaps and could go sideways when you least expect it. As such, you’ll need a qualified team to support your project at every stage. This means migration costs will rise until you get the work done. So, the cost-effectiveness of the conversion tools depends entirely on the type of project.

Originally published at on June 15, 2021.



ModLogix helps organizations move legacy applications to new secure, stable, and scalable platforms. To explore more, please visit

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