I just came back from executing a Ready assessment for a company in Minnesota, where I analyzed 740,000 lines of code in a VB6 application, of which 660,000 belonged to a single Visual Basic project (.vbp). This is actually the largest single .vbp I have seen so far, beating the previous record of about 500,000 lines of code held by an European company. We have migrated plenty of applications that contain 1+ million lines of code, but they are usually distributed across many .vbp’s.
Though unusual, single vbp’s of this size are perfectly manageable from a migration standpoint, and here are some things that can be done to deal with them:
- Ensure that the migration computer has at the very minimum, 3GB of RAM.
- Look for customization opportunities before you start migrating the code. Customizing the VBUC for this specific VBP can reduce manual effort drastically.
- When making manual changes, start with a small team until you get the project to compile, especially if migrating to VB.NET as the compiler has a maximum of build errors that it can show at any given time.
- Once the application compiles, increase the team size and go for Visual Equivalence by distributing the different forms and user controls across your developers.