What Went Right
Platform/language choice was the first and most critical decision we had to make. The legacy product used a custom C-like language. Users only had access to integers, floating-point numbers, and arrays, although they often clamored for language features such as strings, return values from functions, and more robust function libraries. We determined that adding to the existing Micro Saint Sharp platform was not the best option because of time constraints and that we would need to implement future language features ourselves. I strongly felt that we should first look at what was available off-the-shelf before investing in creating software entirely on our own.
We considered using several programming languages, including C++, C#, Visual Basic (VB), Python, Perl, JavaScipt, and Java. C++ was dismissed because of the language complexity and a concern of having modelers crash their applications because of the lack of built-in exceptions. VB, Python, and to a lesser extent Perl did not meet our requirements because the syntax would be unfamiliar to our existing customers. I decided against Java primarily because I encountered problems with it in my previous programming experience. These problems were mostly related to memory consumption and performance—important improvements we hoped to gain with this rewrite. We were left with deciding between C# and JavaScript. Both would have been good candidates for our users from a model-coding perspective. In the end we chose C# for two reasons:
n C# was compiled so we expected to get a big performance boost over our old simulation engine. (In fact, we have seen some simulation models run 1000 times faster over the original tool.)
n C# software developers could be resources to the users/modelers that would be transitioning to the new language.
The main downside to using C# was that users could no longer pause their model, make changes to the code, and then resume it—a capability available in the original version.
Much of the software used in our company is Windows based. In addition, I was comfortable using Visual Studio. Consequently, we opted for this route. Microsoft .NET 1.0 had also recently been released and we chose to embrace it creating the new tool in C#. I have been pleased using C# and .NET, mainly because it offers a great blend between the performance of C++ and the development speed of Java.
