The software was
before I did.
FlexPIPE was not dreamed up last year. The calculation engine is decades old, and that is exactly why it can be trusted.
The original
Written in QuickBASIC
The original FlexPIPE was developed by G.A.P. Heidema. It was a set of separate programs calling one another — a start screen, an input module, a calculation module, a plot module — written in QuickBASIC and running on DOS.
That setup sounds dated, and it is. But it worked. The software was used for years at engineering firms and contractors in the oil and gas industry, on projects where a wrong result would have been expensive and dangerous.
Reference projects of the original software
These companies used the original software. Listing them is not an endorsement and not a current customer relationship — it says something about where the calculation engine comes from, not about who is a customer today.
The problem
Then DOS stopped
Somewhere along the way the software became unusable. Not because the calculations stopped being correct, but because there was no machine left to run it on. That loss is more common than you would think: expertise locked inside code nobody can execute any more.
The rebuild
What was kept, and what was not
I rebuilt the application as a modern desktop app for macOS and Windows 11. In doing so I drew a deliberate line between what you touch and what you do not.
Retained
- The calculation methodology
- The module structure and numbering
- The file formats (.FLX, .OUT, .SUM)
- The material library
Rebuilt
- The entire interface
- The file handling
- The reporting and plotting
- Installation and licence management
Who
Damian de Raad
Studied mechanical engineering at Delft University of Technology, then became a software developer. That combination is why FlexPIPE exists.
A programmer without an engineering background could have ported this code, but not judged what was actually at stake in each decision. An engineer without programming experience would have recognised the value but been unable to act on it. The work sat exactly on that boundary.
In practice it means you can put questions about the calculations straight to me. There is no support department in between having to go and ask.
See for yourself whether it holds up?
Run a project whose result you already know. That is the only test that counts.