Welcome to the Vensim forum, a great place to get fast advice on modeling challenges. The following are some thoughts intended to help you get the most out of the resources here.
- If you're posting a question about a model, give us a little background. What is in the model? What question is it trying to answer? If we know what you're trying to accomplish, we can often suggest new approaches.
- Search the forum first. There are 7 years of answers here. Many are tagged by keywords at http://www.delicious.com/vensimforum. Old bugs have been fixed and new features have come along, so if you don't find an answer that works for you, ask again: you might get a better one.
- If you're having a technical difficulty (bug or error message), tell us what version of Vensim you are using (PLE, Pro, Standard, DSS... ; 5.4, 5.10 ...) and what operating system (Mac, Win7, etc.). Before posting, try upgrading your copy of Vensim to the latest, at http://www.vensim.com/download.html or http://www.vensim.com/buy.html .
- If you are using the Vensim .dll with a programming language like Java or Excel/Visual Basic, you may be better off directing questions about your code to a forum that specializes in the language. We can help with the Vensim function calls, but not necessarily other programming questions.
- If you're attaching a model that uses a non-English character set, post it in a binary format (.vmf or .vpm).
- Use the help system and manuals. While you're in Vensim, go to the Help>Vensim Manuals item. Don't see what you're looking for? Try the Index or Search tab. Help is also online at http://www.vensim.com/documentation/ (hint: you have to double-click the chapter headings in the navigation menu on the left side to open them).
- Define units, and check that they balance. This process reveals many conceptual errors, and makes the model clearer to the reader. Experienced modelers instinctively mistrust models without units.
- Having trouble formulating equations to represent something? Check the sample models that install with Vensim.
- Have a question about system dynamics or modeling in general? Try the SD Society forum: http://www.systemdynamics.org/forum/
- Having a hard time? Don't get discouraged. Modeling is intrinsically harder than making a Powerpoint slide or ordering a book online, but also far more rewarding in the end.