Ventana software support forum

Re: Jim Hines, SD0111, April 30 Forgive me if I did not make myself clear. The oil exploration model is continuous-time in its entirety, all done within ithink. Individual prospects (along with attributes of actual and estimated size) are generated Monte Carlo-style at regular intervals, and they im...

Re: Joel Rahn, Mon, 29 Apr 96 16:39:59 CST >This looks like a Bayesian model with the revision of probabilities >occurring as new data arrives. Are the times at which (or the sequence in >which) new data arrives important for the results (i.e., does it matter if >datum A arrives before datum B, in t...

Jim Hines writes: >Discrete event seems more subtle. I suspect its not well suited to >investigating feedback. But, why? And in another message: >Now, we need to get a little sharper on the character of the understanding that >Discrete Event modeling produces. I said earlier that it has to do with >...

Tacito Nobre wrote: >>I am looking for system dynamics models for the Chemical and Petrochemical industries.<< Many, many SD models have been done for these industries. Of course, much of this work is proprietary, but not all, as youll see by perusing the SD Bibliography. I describe a simple model o...

Responding to two comments by Jim Hines. First: >>What is on the stand is the validity of the logical argument (not the model); and logical argument succeeds or fails by whether it is in fact logical and whether it is supported by the "data" and experience of the audience.<< Like data fitt...

Bill Cutler asked about modeling human motivation, and about fuzzy logic. Human motivation: Psychological SD models with which I am familiar have addressed topics including Hysteria (Wegman 1977), Response to Authority (Richmond 1977), Mid-Life Crisis (Dabiri 1979), Alcoholism (Goluke 1981), Worker ...

The first page of the Business Day section of todays (6 December) New York Times has a fascinating story, "Wild Price Swings at the Pump -- Refiners Gamble on Low Inventories, Insuring Volatility", by Agis Salpukas. I recommend it to all those interested in production-inventory-price dynam...

Speaking of "Success to the Successful", I recommend to all systems thinkers a nifty little article in this weekends (May 5) New York Times Magazine, "Why the Best Doesnt Always Win," by Peter Passell. Passell describes the phenomenon of "path dependence", and gives a n...

In response to Phil Odences question about co-flows: Co-flows are a perfectly fine and time-honored way to model the accumulation of attributes (like age or experience) associated with some underlying physical flow (like people or equipment). They do not conflict with Forresters vision of stocks and...

Joe Kilbride wants to know about proper criteria and methods for determining whether SD is the best tool for the job. As a full-time SD consultant, I am often faced with clients who are already excited about SD based on some previous exposure, but are not sure to which of their own issues it should ...