Vensim 5.9e Is now available including a Beta Release for OSX (Download) New Courses on Climate and intense data use.

Version 5.9d improves usability of SyntheSim and suppresses excessive error messages when checking and simulating models. The installation program has also been changes to allow non-administrative installation.

Portions of the User's Guide have been translated into Polish by Professor Krzysztof Krupa of the Technical University of Cracow.
Version 5.9c (replacing 5.9a) improves display and selection appearances for greater clarity and fixes a number of bugs.

Version 5.9 now supports date labeling for both graphs and table output. This can simplify presentations for models to people more comfortable with dates than decimal time representation. Date labeling is not available in PLE or PLE Plus.See the readme notes for more details.

Version 5.8d has a Japanese interface option and fixes a number of bugs.

Version 5.8c makes compiled models and external functions easier to access from Vensim DSS, the DLL or the Model Reader. It also included a number of bug fixes.

Version 5.8b is now available. This adds in override equations for subscripted models, allows nesting of macro definitions, provided control over messages displayed during a simulation and fixes a number of bugs.

Version 5.8a is now available. This includes a number of small bug fixes.

Version 5.8 is now available. This includes a number of usability and performance changes, including the addition of a single equation Document tool for PLE and PLE Plus. We have also included a version of the World3 model that makes it much easier to replicate scenarios in the book the Limits to Growth.

Version 5.7a is now available. This version fixes a number of bugs, especially related to Spreadsheets with international characters in their names and Reality Check. It is also now possible to add a variable and its causes to a sketch in Vensim PLE and PLE Plus.

Version 5.7 is now available. This adds Unchangeable Constants, considerable performance improvements during optimization and a new VECTOR SELECT function that simplifies subscript relationship management.

Version 5.6b is now available. This version adds in the capability to apply the Graph, Strip Graph, Table, Sensitivity Graph, Stats and Document tool to multiple variable selections making it easier to look at a collection of variables together.

Version 5.6a is now available. This version supports Unicode and increases the functionality of the Vensim Model Reader to be able to open Venapps and Vensim DLL based applications. PLE Plus also supports hiding in this release.

Version 5.5d of Vensim is now available making it simpler to share your models with others and to control the way others can access your work. The new package publication feature allows you to send everything needed to run a model in a single file making sure the people you send it to see what you see. It also allows you to mark models so that they can't be changed by the people receiving them. In addition there are a number of smaller changes, new functions and problem corrections.

Version 5.4 - Vensim PLE now supports input output objects and allows you to override behavior in SyntheSim. These changes are aimed at making PLE more effective an all teaching environments.

Vensim 5.3a is now available for downloading. A number of small improvements have been made to 5.3 which included new navigation capabilities, more hide levels with layered simulation, better pasting and improved performance with nonstandard character sets.

We have also increased the functionality of Vensim PLE to support the creation of models with multiple views and make use of data.

Shanghai eyDao IT Company becomes distributor for China

Distance Program in System Dynamics at WPI!

Worcester Polytechnic Institute (WPI) is now offering a distance program in system dynamics. There are a number of courses currently available, and more will be added. The courses can be used to receive a certificate in system dynamics or as part of a Masters in Systems Modeling.

Customer Applications

We have just added a new section to our website to describe what our customers are doing with Vensim. If you have something you would like to share let us know.

Vensim Discussion Forum

Ventana Systems UK, our distributor in Great Britain and the producer of the Sable software for developing interfaces to Vensim models has created a discussion forum for technical and other issues relating to Vensim. All are welcome to participate. The forum is located at http://www.ventanasystems.co.uk/forum and is open to everyone.

Now it is easier than ever to create the tools you need for your enterprise modeling requirements. The new ODBC connectvitiy in Vensim DSS version 5.1 means that you can seamlessly link your Vensim models with enterprise data sources both to provide data to your Vensim model and to provide Vensim results to your enterprise. The new ODBC functionality makes it easy to get data out of most databases and to write the results back to those databases. You can transfer values for Constants, Data and Lookups back and forth automatically as simulations are run.

Version 5.1 also has a number of new functions aimed at making it easier to do financial computations the same way they are being done with other modeling tools. Vensim lets you specify the fiscal period you want to work with so that your model can be run using the most convenient time base. The financial functions summarize over the chosen fiscal period making it easy to get annual computations with a monthly model. The new functions include support for straightline and scheduled depreciation, the internal rate of return and a new net present value function. In addition, we have added in GET XLS LOOKUPS so that you can now easily get Constants, Data and Lookups from spreadsheets.

We have generalized the old ALLOCATION BY PRIORITY function to give you more control over how things are allocated and also fixed a number of small problems.

Mohaseboon becomes distributor for Egypt and Middle East

Partial Translation of User's Guide to Spanish (now with Chapter 15).

Vensim 5 with SyntheSim and New Graphs

Vensim version 5 is now available. With version 5 you can see the results of your simulation experiments as you make them. Vensim will instantly simulate your model and display the results as you move sliders. You don't even need to change your models - Vensim will add the sliders automatically. SyntheSim is available in all Vensim configurations.

Other improvements: More functions including DELAY_CONVEYOR, DELAY_BATCH, LOOKUP_INVERT and LOOKUP_SLOPE. Single click selection speeds analysis. A model comparison function makes it easier to track changes. See the complete documentation online for more details.

Release 5.0c adds some functionality to the Equation Editor and also exports information from the Table and Stats tools in native Excel format to ease interaction with spreadsheets. We have also added a new Table tool to Vensim PLE, PLE Plus and the Model Reader that has time running down and should be easier to work with for models with long simulation ranges.

With version 5.0b we have added in more styles for custom graphs including 3 D and Ribbon graphs.

If you purchased a new license for Vensim after October 1st, 2001 you are entitled to a free upgrade. You can download now (you will need your registration code). If you bought before October 1st, 2001 you will need to upgrade. If you purchased new license in 2001 or upgraded to version 4 in 2001 you will, for a limited time, receive a discount on your upgrade to version 5.

Your purchase of Vensim 5 includes free updates for one year from our website. Just check back from time to time to see what has changed.