Development – top-down, inside-out, middle out ? ? ?

I recently came across this post, from the development log for Microsoft’s Visual Studio tools – I know it’s dated 2005, but some of the points are relevant. He believes that the approach that IEF took -which was a totally model-driven approach (he was on the design team in the late 1980′s/early 1990′s) could be successul, but now a “nimbler way forward” is better.

I believe that he says this because he is an advocate of Domain Specific Languages, and that for each specific role in a large enterprise, a specific DSL should be chosen, and that they be integrated by standards-based connectivity. Gen is, as he puts it, entirely self-contained. He advocates replacing the model with source code control.

I would put it a different way.

Source code control, to me is a backward step, and model-based development is a forward step ! I do agree with what he says, though on standards-based connectivity between disparate technologies. DSL’s have been around for years – haven’t they ? We used assembler for the low-level, fast, intricate stuff,with COBOL for the bulk data-processing elements of the system.

What was missing then was the standards based connectivity between parts of systems. Now we have that, all is well, since as long as Gen can adhere to the standards, then Gen can be part of the “new world”.

Gen (in my mind) could be considered a DSL, BEST SUITED for enterprise-scale, reliable data processing operations.

In addition, Bill thinks that a code and model approach is also required, presumably with a two-way interaction between the model and the code and the code and the model. I don’t believe this in a Gen environment, since Gen’s strength is NOT allowing the developers to see the code, and allowing them to violate model constraints – also, having direct access to the code assumes a specific target platform – how many of Microsoft’s tools can deploy the same piece of business logic on a mainframe, PC or Unix server ???.

Microsoft’s way forward with these tools assumes a Windows environment – there is a world outside Windows !!!