Ventana software support forum

Wow, there are sure a whole lot of interesting debates that Jim Hines questions triggered. I fear we need to break this thread into several, so we have some chance of keeping them separate. The title of the thread, I note, is still "Using Statistics in Dynamics Models" -- thats "in&qu...

I believe that Fujio Cho is simply reflecting the Deming philosophy when he refuses to set sales quotas. Dr. Deming was adamantly opposed to any kind of "management by objectives" for reasons such as Fujio Cho cited and others. He taught the Japanese, and they learned very well, that the o...

I agree with John Swanson -- we need to be able to justify that a model is worthy of being used, not engage in sophism that goes deeply into the philosophy of science. (Books have been written on the verifiability/validation of scientific theories but citing them doesnt help someone very much who ha...

Having heard the previous discussions and the response by Finn Jackson, and appreciating the conclusions reached -- it still may be said that there has been a lot of practical and, less often, verifiable research done on the sales process. Whole books have been written on what makes a good salespers...

Kim, Im responding to two interesting points not having to do with your main question. 1. There is one assumption you state that is not always the case. You say, "... and crucially ... those rates of change in asset-stocks are themselves, like all other variables, dependent upon the current lev...

Yeah, its a classic for SD and its also an example of one of Demings "rules of the funnel" where "tampering" with the system (making decisions about the future based on what happened to your just-past decision) just increases the variability of the system. Its fairly common knowl...

Ill venture a partial reply. (Im not prepared to respond to all of the "windup" to the "pitch," but Ill respond to the "pitch" which I take to be your question about whether System Dynamics has "anything fundamental or unique OF ITS OWN to say about the way the uni...

Id like to risk being a voice crying in the wilderness here and suggest that "having economic models of everything" and moving toward "accounting based decision support tools" may NOT be progress. Rather than repeat the argument here I would refer interested readers to Demings &q...

Steve, just a quick note in response to your request. It seems to me that one of the most relevant topics to include, from an SD modeling perspective, might be called "How to avoid creating a crisis" since many organizational crises are of endogenous origin -- often the result of trying to...

Bill, One idea: Look at Stermans examples of coflow structures to track forecasts. For example, p. 457 of his "Business Dynamics." Also, look at p. 837 (part of the Commodity Cycle model he based on Dennis Meadows earlier work) where changes in price are used to compute an "Expected P...

In all this discussion of "good" vs. "bad" idea -- i.e., to develop software that extracts stock-and-flow models from textual description of a system -- there is one thing I havent yet heard. If such software existed (and worked) it would, of necessity, create a disciplined appro...

Id just like to add a comment to Dr. Forresters remarks. He wrote: "Perhaps the emphasis should be placed on interview processes, what to look for in listening, what kinds of questions to ask, and how to dig below the surface for information that is not initially forthcoming." For what its...

I want to try to respond directly to Niall (and, by implication, to all those who may feel similar things.) Niall, I very much appreciate your courage and candor. My response has two quite different parts. First, ironically, as I have read the messages in this list over the past couple of years, Ive...

George, I absolutely love your idea of asking experienced modelers to create models from the same written description, then asking them to describe their thinking processes. (There are, I believe, some formal ways of asking them to describe their thinking.) I would like to suggest that, if anyone is...

No, its not unreasonable to suggest that discussants join the Society
since it would actually be doing them a favor by putting them in touch
with all of the Societys resources. Going any further than suggesting,
however, is not wise.

John W. Gunkler
jgunkler@sprintmail.com

To Dr. Coyle -- HOWL! When you write, "Even if you agree on the meaning of 1, what does 0.5 on Johns scale mean?" it seems as if you are unaware of the decades of research in the psychology of sense perception. Psychologists have had very good luck with, to mention but one example, a metho...

Mark Mackay asks if there is a role for SD in community health where little "evidence" is quantitative. I think there is. My first thought: Model your (and other community health professionals) assumptions about specific problems and solutions. Even though you say quantitative evidence is ...

I would like to suggest that perhaps it is partly Geoff Coyles use of the term "rate-dependent rates" that is confusing people. I may be wrong but I dont believe you will find the term "rate-dependent rates" in any of Dr. Forresters works. Certainly he does (and does it very clea...

Okay, Ill risk humiliation by responding in favor of graphics-based SD software. Geoff Coyles complaints, ending with "By my count that is five tasks, some laborious and unproductive, when a single simple one is all that is needed." sound a lot like Andy Rooney complaining about having to ...

A lot of the good thinking and writing on causality, at least when I learned about it, was done primarily in the context of the physical sciences. Much of it (Karl Poppers work in particularly, which has been mentioned by several people already) is very useful in any field. I also find that William ...

To George Backus $100 contribution I have two cents to add. George wrote: "All decisions affect flows. The flow affected can only go between 0 and 100% of its potential value." While this sounds logically irrefutable, it raises a red flag for me. The issue is who determines what the "...

Since this is all highly speculative, might I contribute a further dynamic hypothesis? If Elvis felt that taking drugs was necessary for him to continue performing, and if the Colonels bankroll depended upon Elvis continuing performance, there would be a more than "unconscious" link betwee...

Since this has become a discussion thread, rather than an immediate response to Nialls need, I thought someone should mention the obvious: Dennis Meadows and Linda Booth Sweeneys Systems Thinking Playbook, Vols. I and II -- games for use in K-12 classrooms. If anyone is still looking for demonstrati...

While not specifically addressing the growth of churches, there are some "classic" articles on the multi-stage growth of organizations (in general) that would apply quite readily to churches. The seminal article (in my opinion), by Larry Greiner, "Evolution and revolution as organizat...

Rather than create an equation for "safe following distance" which depends on many factors, primarily the speed of the vehicles, perhaps you can simplify by assuming that (at any speed) the following vehicle must be (a constant) three seconds behind the one in front. I know that this is a ...