Search found 80 matches

by Jim Hines
Mon Dec 14, 1998 8:50 am
Forum: SD Mailing List Archive
Topic: Who introduced causal-loop diagrams
Replies: 3
Views: 5443

Who introduced causal-loop diagrams

Ed Roberts once told me that he introduced causal loops.

Jim Hines
MIT and LeapTec
From: Jim Hines <jimhines@interserv.com>
by Jim Hines
Fri Nov 20, 1998 9:18 am
Forum: SD Mailing List Archive
Topic: Fisheries Management
Replies: 1
Views: 9537

Fisheries Management

Jody House and Babette Wils, working with Dana Meadows, have done very
interesting work on the Shrimp industry (wild caught and culture). Their
emails are JHouse@MIT.EDU and wil@vassar.edu (maybe, wils@vassar.edu).

Regards,
Jim Hines
From: Jim Hines <jimhines@interserv.com>
by Jim Hines
Sat Nov 14, 1998 11:22 am
Forum: SD Mailing List Archive
Topic: Modelling Manufacturing Systems
Replies: 2
Views: 10175

Modelling Manufacturing Systems

John Morecroft (Professor, London Business School) has done work in
these areas. His doctoral dissertation was on MRP. Influences from
Information Technology on Industry Cycles, 1979, M.I.T.

Jim Hines
MIT and LeapTec
From: Jim Hines <jimhines@interserv.com>
by Jim Hines
Sat Nov 14, 1998 11:16 am
Forum: SD Mailing List Archive
Topic: Whole Systems
Replies: 7
Views: 17428

Whole Systems

Nugent, Michael D wrote: > Question (not criticism): > When the focus is profits, why would not a systems (e.g., a > businesss) suppliers and customers and regulators (and international > economic cycles, emerging technology, etc.) be included in "everything we > believe must be included in ord...
by Jim Hines
Tue Nov 10, 1998 11:52 am
Forum: SD Mailing List Archive
Topic: modeling systems
Replies: 6
Views: 18349

modeling systems

Bill Buchanan wrote: .

> ...Of course whole "systems" can be modeled. ... Examples abound,

People on this list would disagree that any of your examples is a "whole" system.

Regards,
Jim Hines
MIT and LeapTec
From: Jim Hines <jimhines@interserv.com>
by Jim Hines
Fri Nov 06, 1998 10:44 am
Forum: SD Mailing List Archive
Topic: Systems of problems
Replies: 5
Views: 7789

Systems of problems

Bill Braun wrote "...Akoff said that one aspect of applying systems thinking was to think in terms of systems of problems...If SD is best suited to exploring problems, and problems are considered from an interlocking, interdependent systemic point of view, why is it not reasonable to model larg...
by Jim Hines
Tue Nov 03, 1998 2:02 pm
Forum: SD Mailing List Archive
Topic: College drinking
Replies: 8
Views: 10241

College drinking

Khalid, Im not clear on what goal is sliding. The drinkers goal remains to be socially at ease. Also, as much as we would like to think that drinkers are social outcasts, Im not sure thats the case. An unfortunate process might involve a positive loop in which drinking becomes increasingly acceptabl...
by Jim Hines
Fri Oct 30, 1998 9:28 am
Forum: SD Mailing List Archive
Topic: College drinking
Replies: 8
Views: 10241

College drinking

Van Bowen, What is the reference mode? I think it is that college drinking (and use of drugs) is and has been high for decades. Why? (Alternatively, it could be that **concern** about college drinking is rising -- why?). If the issue is college drinking itself: I think that one dynamic hypothesis is...
by Jim Hines
Thu Oct 22, 1998 9:08 am
Forum: SD Mailing List Archive
Topic: Object Orientation Challenge in S/W Projects Management & SD
Replies: 3
Views: 5884

Object Orientation Challenge in S/W Projects Management & SD

Id approach this by starting with the project model and considering how OO would impact it. For example, productivity and quality of a new component would probably be low, while productivity and quality for reuse would be high. The functions relating fatigue to its effects on productivity and qualit...
by Jim Hines
Wed Oct 07, 1998 10:12 am
Forum: SD Mailing List Archive
Topic: Validity of Models
Replies: 4
Views: 6939

Validity of Models

This is a response to John Gunklers thoughtful posting (1) I predict that the word "prediction" is going to cause problems in this discussion. Some people (like me) think of it as meaning "point prediction", others (like David Peterson) think of it as meaning any statement about ...
by Jim Hines
Tue Sep 15, 1998 12:49 pm
Forum: SD Mailing List Archive
Topic: Work on Water Resources
Replies: 4
Views: 13645

Work on Water Resources

Abdul,

Could you be more specific? What issues are you interested in? What
reference modes?

Regards,
Jim Hines
From: Jim Hines <jimhines@interserv.com>
MIT
by Jim Hines
Tue Sep 15, 1998 12:46 pm
Forum: SD Mailing List Archive
Topic: The Hard Core of SD
Replies: 7
Views: 7704

The Hard Core of SD

Concerning George Richardsons reply:

Well, gosh, George, tell us what you SAID in all of those places.

Jim
From: Jim Hines <jimhines@interserv.com>
by Jim Hines
Fri Aug 28, 1998 11:38 am
Forum: SD Mailing List Archive
Topic: international trade models
Replies: 3
Views: 5932

international trade models

Jeff, It would help us a lot if you could be a bit more specific about your SD focus on international trade in maize. You might want to give us a key reference mode: Is your issue, for example, that trade has been declining (or growing or stagnating)? Is it that prices have been rising (or falling o...
by Jim Hines
Wed Aug 19, 1998 11:50 am
Forum: SD Mailing List Archive
Topic: systems or reference modes?
Replies: 3
Views: 6276

systems or reference modes?

Drews more specific statement of the forest problem should serve as an example for us all. There are several ways to get specific, reference modes are one of the best. Drew asks: "It is well accepted that the "model the system" trap is a particularly nasty one, but does the same lesso...
by Jim Hines
Tue Aug 11, 1998 1:44 pm
Forum: SD Mailing List Archive
Topic: SD Self-Study Curriculum
Replies: 4
Views: 6811

SD Self-Study Curriculum

This is a response to Bill Brauns request for thoughts on self-study. There are a number of possibilities. But, first your statement: >I sense that I am particularly ill prepared from an algebraic >point of view. A facility with algebra is necessary for modeling. If you havent used algebra, for awhi...
by Jim Hines
Mon Aug 10, 1998 9:15 am
Forum: SD Mailing List Archive
Topic: Application of SD to Risk Manageme
Replies: 8
Views: 8780

Application of SD to Risk Manageme

A short build on Bob Eberleins excellent point that multivariate sensitivity analysis can help us ".. see whether there are combinations of parameters that put the model into different behavior regimes." Bob says this "allows you to have more confidence...". It also may guide you...
by Jim Hines
Thu Jul 30, 1998 10:59 am
Forum: SD Mailing List Archive
Topic: Systems from the top?
Replies: 26
Views: 54844

Systems from the top?

Just a clarification to Jay Forrests comments: > >3) How to "sell" the conclusions of an SD process to the rest of a > >company. Jay wrote: > As a facilitation oriented consultant, I believe "selling" the conclusions > includes connotations which doom the consultation. The need t...
by Jim Hines
Mon Jul 27, 1998 9:17 am
Forum: SD Mailing List Archive
Topic: Systems from the top?
Replies: 26
Views: 54844

Systems from the top?

This is a reply to Van Bowen, who asked > Does anyone have information concerning > system dynamics being the way of thinking at all levels of > any company? You have put your finger on the current challenge in applied SD. Its no longer unusual to find a SD project being done at a (large) company. H...
by Jim Hines
Mon Jul 27, 1998 8:38 am
Forum: SD Mailing List Archive
Topic: models of forests and forest economies
Replies: 4
Views: 6049

models of forests and forest economies

This is a reply to Drew Jones posting, and is only offered because Drew is such a terrific SDer and should be setting the pace for the rest of us! Drew wrote: >We are seeking system dynamics models that investigate: > >1. the dynamics of forests, and/or >2. the interactions between forest ecosystems...
by Jim Hines
Thu Jul 09, 1998 10:42 am
Forum: SD Mailing List Archive
Topic: System dynamics in K-12 education
Replies: 9
Views: 9214

System dynamics in K-12 education

Concerning Guenther Ossimitz interesting post about his investigation
into the difficulties that 14 and 15 year olds have with SD:

A control group of adults would have been interesting. My guess is
that adults have the same difficulties.

Regards,
Jim Hines
LeapTec and M.I.T.
JimHines@Interserv.Com
by Jim Hines
Mon Jun 29, 1998 9:04 am
Forum: SD Mailing List Archive
Topic: Causal Loop Diagraming Tool
Replies: 7
Views: 10305

Causal Loop Diagraming Tool

Vensim can create neat causal loop diagrams (as well as stock and flow
diagrams). Also, you can create simulation models from causal
loops,from stock and flows, or any mixture of the two formats.

Regards,
Jim Hines
MIT and LeapTec
From: Jim Hines <jimhines@interserv.com>
by Jim Hines
Sat Apr 25, 1998 5:54 pm
Forum: SD Mailing List Archive
Topic: Published, quantifiable results
Replies: 2
Views: 6424

Published, quantifiable results

Fabian H. Szulanski wrote: > > Hello Chris, > There is one case that I recall, it is related with a legal battle > between the US State and a ship building company called Halter Marine, The original work was done by Pugh-Roberts and involved building a project model to support a claim by Halter Mari...
by Jim Hines
Sat Apr 18, 1998 10:45 am
Forum: SD Mailing List Archive
Topic: Some questions Re:accreditation
Replies: 9
Views: 23295

Some questions Re:accreditation

Alans thesis is wonderful. You might be interested in knowing that Alan is with Pugh Roberts. In addition to being one of the leading system dynamics folks he is also an expert in TQM (and has a relatively recent book out in that field). If you liked Alans thesis, you might also be interested in Nat...
by Jim Hines
Thu Apr 16, 1998 10:45 am
Forum: SD Mailing List Archive
Topic: Some questions Re:accreditation
Replies: 9
Views: 23295

Some questions Re:accreditation

Actually I liked Toms injunction to - thou shalt perform parameter change experiments one at a time. Changing parameter values one at a time is directed not toward getting confidence bounds, but rather toward understanding the model. The injunction should probably be: - thou shalt take the time to u...