Ventana software support forum

One questions the work of the Gods of system dynamics (Forrester et al.) at extreme peril, but there were some major flaws with the original Club of Rome work as I recall. As I remember it, the key problem was the absence of a supply/demand mechanism as per economic theory. On the supply end, the wo...

To those who wrote to me asking for further information on the models I have been working on: My apologies for delaying so long. I am happy to announce that I have set up a web site where you can download these models and papers. The URL is: http://qlink.queensu.ca/~4jds/index.html The models which ...

I would be interested to hear more about how you are using ecologically based models for new product introductions. How do these models distinguish between such things as product repurchasability? Products that are purchased only once, will climb to a peak and then decline, while repurchased product...

It is not realistic to maintain a consistent numerical scale when you are plotting different variables, but a rule of thumb that I try to use is to make the origin (bottom left of the graph) start at zero if possible. It is easy to distort graphs by choosing a non-zero origin such that minor variati...

I am not sure if this is what you had in mind by assymetric information, but some of the models I have been working on recently have dealt with assymetric information in the context of modelling market share change. I have posted to the group in case anyone else is interested... If not surf on! Info...

Hi, my name is Jonathan Segel. I have been working on a systems dynamics model of market share change within an oligopolistic market. The specific area towards which I am aiming it is competition for long-distance telephony services, but I have also adapted a version for modeling market share in a r...