Ventana software support forum

Phil Odence wrote: > My take was that Kim was saying feedback IS as basic as integration, AND > integration (I prefer accumulation) is as basic as feedback. Stock flow maps > give us both. CLDs convey part only part of the story. I think (no pun intended) I agree with the above. I have thought a lot...

Jennifer Espey wrote: > I was wondering if anyone knew of an application(s) of system dynamics to cultural change. Peter von Stackelberg built an interesting model of resistance to change that might inform you about one aspect of cultural change. Ive done a lot of "systemic" thinking in th...

Colleagues, Just a quick note ... I was listening to National Public Radios Morning Edition late last week and heard a segment about the IMF (or was it the World Bank?) using the Vensim simulation model Threshold 21 as a way to make investment decisions in countries. It talked a bit more about SD (w...

Jim Hines comment prompts my thoughts: > I like Khalids suggestion. The society should now encourage > university-level **programs** in system dynamics. I think the society could > come up with a set of courses that should be included in a certified SD > program. I think the promise of certification...

Tall order. Short answer, yes, SD would be useful. But ... its nearly impossible to choose appropriate variables and boundaries using an "Id like to understand the system" approach. Start with a concrete problem statement, including a specific variable, the behavior of which can be seen to...

Bruce Campbell wrote: > Does anyone know of a PC based causal loop diagraming tool, and its > details? > Well, tehres always VENSIM, which allows CLD structure, but also lets you model straight from there (a nightmare, actually!). You need a lot of experience, much more than I have, to mix CLD and S...

I had planned to maintain silence on this issue, but Jay Forrests impassioned and well reasoned argument forces me out of the closet ... to agree with him. One of the more challenging aspects of SD is that it has very little utility when pure; it must be used in the service of other disciplines or e...

VENSIM does a little of this with sensitivity analysis, but wht you are looking for is the functionality (in an SD environment) of a product like @RISK. It isnt at all "SD like" (works inside spreadsheets), but if you have a formula, it will let you model the distributions of a bunch of in...

George Richardson wrote: > I recall hearing one of the authors of "Mankind at the Turning Point" by > Mesarovic and Pestel (a book published by the Club of Rome after "Limits > to Growth") claim the same theorem mentioned in this query. Mr. Winston > may find a reference in that ...

George Richardson wrote: > I recall hearing one of the authors of "Mankind at the Turning Point" by > Mesarovic and Pestel (a book published by the Club of Rome after "Limits > to Growth") claim the same theorem mentioned in this query. Mr. Winston > may find a reference in that ...

I recall Margaret Johnson at Stanford was working on a flight simulator for the IT organization, and she and David Bartz had started working on some videotapes of various system dynamic tools, with an emphasis on software engineering as their example. -- Stephen B. Wehrenberg, Ph.D. Chief, Forecasts...

Though I can add nothing of great substance here (lord knows Ive experienced it often enough, though!), I would be very interested in hearing the replies ... James, if you get anything not posted to the list, please share it if appropriate. The moral high ground here is "If the organization is ...

patricio rodriguez valiente wrote: > Who can tell me where i can obtain the papers that reference in Road Maps 8: > I have Part 11: Conceptualization and I am looking for the rest: > Formulation > Testing > Implementation Patricio: The bad news is, youll have to wait for further installments. RM8 ha...

Donella, et. al. Im certainly with you from 1 to 8! That fits nicely into zillions of years of research in organizational psychology, org structure, and management theory. Actually, thats true down to 6, and my own limited use of system dynamics leads me to believe that 7 and 8 are in the right orde...

Don ... the @RISK package does just what you say ... available from Palisade ... see their web site at http://www.palisade.com Now if it could only interface with an SD modeling package ... sigh. Steve -- Stephen B. Wehrenberg, Ph.D. Chief, Forecasts and Systems, US Coast Guard; Administrative Scien...

Colleagues: Just read the Feb issue of Atlantic Monthly; therein an interesting article by philanthropist George Soros on the dangers of capitalism. What makes it interesting to me (and, potentially, us) is the perspective he brings to the argument. In essence, capitalism only works in theory, and t...

I urge you to peruse the Creative Learning Exchange and Systems Dynamics in Education sites. The ROADMAPS series is particularly useful in putting theory into practice, albeit on a rather small scale. You will be able to reach Jay Forrester by e-mail at this site. Also, the High Performance Systems ...

Colleagues: Ive wandered the virtual halls of MIT today looking for an SD Group memo, D-2508-1. No luck ... too old, I guess. The paper is by Barry Richmond, 1977. _Generalization and Individual Uniqueness: Modeling the Milgram Experiments_. Ill contact HPS and try to get a note to Richmond, but in ...

Vensim has a nice demo and free "Personal Learning Edition" at their home page, http://www.std.com/vensim/VENSIM.HTM. Powersim Institute home page is http://www.psiminst.com/ ... dont recall if their demo cersion is on line or if you ahve to ask for it. Its quite a package, 4-5 floppies. S...

Colleagues: I have sent this to LO, sys-dyn, and SUN lists ... if you receive more than one, my apologies in advance. At the SD Conference in Boston this week, Fred Affeldt (GDSS, Inc) and I ran into a number of Washington DC area folks who are either journeymen SD modelers, sorcerers apprentices, o...

Gene, At the risk of Bob wondering why we are having a discussion like this on the list (a reasonable question) ... I read the below, and your paper on translating CLDs to SF diagrams ...as usual, I wont try to answer your questions but will try instead to add to the confusion amd your frustration. ...

CrbnBlu@aol.com wrote: > I have gotten to a point of asking, "Is it possible to develop a tight > method by which Systems Thinking Diagrams (or CLDs) can be reliable > translated to Stock and Flow diagrams for the purpose of conducting > simulation?" Gene: I have been in correspondence wit...

Barry Richmond (HPS) displayed a model of resistance to change a couple of weeks ago in Boston at the Systems Thinking Conference. You can reach him through the HPS web page at ww.hps-inc.com. I vaguely recall Peter Von Stackelberg doing something similar (same outcme variable, different causes and ...

Paul and Gene ... technically, a CLD makes it difficult to distinguish conserved flows and non-conserved flows (information about stocks). As you said to me in private corresp[ondence, Paul ... it depends ... on your objectives as a modeler / learning facilitator. Steve -- Stephen B. Wehrenberg Chie...

Gene, "We choose what we believe and then we believe what we choose." The circle of inference, eh? Senge likes to depict it as a ladder, but its clearly a circle. Your original comments have certainly started a conversation, if nothing else. As A. Einstein said, "The important thing i...