Search found 44 matches
- Fri Nov 17, 2006 12:41 pm
- Forum: SD Mailing List Archive
- Topic: QUERY Beer Game Simulation Model
- Replies: 3
- Views: 22084
QUERY Beer Game Simulation Model
Posted by yaman barlas <ybarlas@boun.edu.tr> Dear Abhijit; Short answer to your question is 'yes' there are such simulation models. More specifically, a couple of years ago we created a model that EXACTLY replicates the physical beer game. The related article is in the proceedings of ISDC 2005, Bost...
- Thu Nov 04, 2004 5:48 pm
- Forum: SD Mailing List Archive
- Topic: Discrete-flow modelling for business simulation
- Replies: 7
- Views: 7260
Discrete-flow modelling for business simulation
Dear Magne; I see your points and agree that integer and/or logical variables are sometimes needed for better, more compact formulations. I think this little debate is about 'degree', not 'kind'. So although I have no problem with your arguments in general, I am also adding the following caution: In...
- Mon Oct 25, 2004 8:12 am
- Forum: SD Mailing List Archive
- Topic: Discrete-flow modelling for business simulation
- Replies: 7
- Views: 7260
Discrete-flow modelling for business simulation
Hello Magne; I now understand what it is you try to do and why you would need a stock. Thanks for detailed explanation. You are right, you do need a stock in this case. Having said this, let me add that I personally do not think a 'special' stock-flow definition and technology is needed to achieve i...
- Wed Oct 20, 2004 6:10 pm
- Forum: SD Mailing List Archive
- Topic: Discrete-flow modelling for business simulation
- Replies: 7
- Views: 7260
Discrete-flow modelling for business simulation
Dear Magne; There is one part in your message that I do not understand. (Below). Although you are technically solving an integer flow and stock problem, WHY would one use such a stock? A stock means, your 'logical flows' would accumulate. You correctly state that a non integer 'true' is meaningless....
- Tue Oct 12, 2004 5:16 pm
- Forum: SD Mailing List Archive
- Topic: Dynamical Systems and System Dynamics ??
- Replies: 12
- Views: 19285
Dynamical Systems and System Dynamics ??
Hello Esteban; Here is one way of characterizing the relations between dynamical systems and system dynamics: system dynamics is the name adopted by a community who does work on dynamical systems of certain type (policy problems of socio-economic or strategic management nature) with a special focus ...
- Wed Sep 08, 2004 5:21 pm
- Forum: SD Mailing List Archive
- Topic: Project Management Flight simulator
- Replies: 2
- Views: 5190
Project Management Flight simulator
Hello all; This is in response to Ilir Rodiqi's inquiry about a week ago. We indeed have a PM flight simulator.(SOFTSIM). Its essential structure is Tarek Abdel Hamid's software project management structure. We simplified some parts and added some structures so that it can be used as a more general ...
- Mon Jul 05, 2004 10:43 am
- Forum: SD Mailing List Archive
- Topic: Modelling ERP/MRP and Common Inventory Policies
- Replies: 3
- Views: 5282
Modelling ERP/MRP and Common Inventory Policies
You may find this useful -albeit indirectly and partially related to your question: We have done some work on testing the standard inventory control rules (such as (s, Q), (s,S), (S, R), (s, S, R)) in a dynamic feedback context. We modeled and replicated them in stock-flow jargon. Results are summar...
- Sat Jan 10, 2004 6:53 pm
- Forum: SD Mailing List Archive
- Topic: Can SD models be validated without being run?
- Replies: 38
- Views: 27853
Can SD models be validated without being run?
Hi Kim, I am not sure I understood all of your questions, but I will reply anyway with few things I know: I- A good (and important) part of model validation is done WITHOUT simulation: I call this direct structure testing. This means establishing confidence in the validity of each equation one by on...
- Tue Dec 02, 2003 12:04 pm
- Forum: SD Mailing List Archive
- Topic: Manufacturing Control Systems
- Replies: 30
- Views: 52565
Manufacturing Control Systems
Jim, If our purpose is to choose a single term and If I had freedom to choose from scratch, I would get rid of the term event because it is this term that would cause problem in the continuous worldview. But since the term event is so established in the discrete community, I have no such freedom. An...
- Thu Nov 27, 2003 1:38 pm
- Forum: SD Mailing List Archive
- Topic: Manufacturing Control Systems
- Replies: 30
- Views: 52565
Manufacturing Control Systems
2 I mostly agree with Jim Hines explanation of events vs. time. The only part I have diffculty adopting is a continuous event. I would either call it a series of discrete events ( in the discrete-time case) or something like a process in the continuous-time. ----- In any case, the other part of the ...
- Thu Jun 05, 2003 12:09 pm
- Forum: SD Mailing List Archive
- Topic: Systems Dynamics Models for Higher Education
- Replies: 6
- Views: 11275
Systems Dynamics Models for Higher Education
Michael J Schwandt wrote: > ... What models exist that cross institution boundaries and consider > broader systems? We have a model that models the National higher education system of Turkey, starting with high school graduation, the central placement exam, placement, enrollment and finally graduati...
- Thu Jun 05, 2003 10:23 am
- Forum: SD Mailing List Archive
- Topic: Systems Dynamics Models for Higher Education
- Replies: 6
- Views: 11275
Systems Dynamics Models for Higher Education
Hello, There has been similar queries in the past. I am pasting our typical reply (apologies to those who have read this before): We have an interactive simulation game for university management (UNIGAME) here at Bogazici. We can send it free for personal educational esearch use. Please contact us i...
- Wed Jun 04, 2003 8:41 pm
- Forum: SD Mailing List Archive
- Topic: Traffic jams and congestion
- Replies: 8
- Views: 12056
Traffic jams and congestion
This is a delayed reply to the "traffic congestion" query and a couple of related notes. A couple of students in our group did a nice modeling project of the dynamics of bottlenecks/gridlocks caused by *feedback effects* at intersections. (I believe Bill Braun referrred to this phenomenan)...
- Fri May 02, 2003 7:05 pm
- Forum: SD Mailing List Archive
- Topic: Can system dynamics models "learn"
- Replies: 46
- Views: 33849
Can system dynamics models "learn"
Part of this discussion (on learning) has dealt with "Models which add, delete, or edit its own equations..." as a definition of learning(1). Most comments on this topic went on to state that "such self-altering models are not achievable in Stella, Vensim of Powersim"(2). I would...
- Wed Apr 30, 2003 7:59 pm
- Forum: SD Mailing List Archive
- Topic: Channel Systems
- Replies: 5
- Views: 5284
Channel Systems
We did a research a few years ago on strategies of insurance management. In this problem, policies are sold thru two different channels: a- agencies, b- direct marketing salesforce. The problem can be very interesting, because the two channels have different structures, needs, motivations and contro...
- Sun Apr 20, 2003 3:27 pm
- Forum: SD Mailing List Archive
- Topic: Can system dynamics models "learn"
- Replies: 46
- Views: 33849
Can system dynamics models "learn"
Depending on what is exactly meant by "learning", this question may have different answers: - A simple negative (goal-seeking feedback) loop involves learning: An action is taken, the result is measured and evaluated, and it is "learned" that the action was either insufficient/in...
- Fri Apr 19, 2002 4:46 pm
- Forum: SD Mailing List Archive
- Topic: SD and University Management
- Replies: 1
- Views: 2732
SD and University Management
We have an interactive simulation game for university management (UNIGAME) here at Bogazici. We can send it free for personal educational esearch use. The primary author of the product is Vedat Diker, now at Albany. And here is the basic reference: ÒA Dynamic Simulation Game for Strategic University...
- Thu Apr 18, 2002 6:22 pm
- Forum: SD Mailing List Archive
- Topic: System Dynamics for Agriculture and Business
- Replies: 2
- Views: 3711
System Dynamics for Agriculture and Business
We have been doing a "potentially" related research: Long-term agro-socio-economic dynamics of irrigation-based regional development projects. The specific context is GAP (Southeast Turkey development project). There has been a PhD thesis and a few papers published. The work continues. If ...
- Thu Apr 11, 2002 7:44 pm
- Forum: SD Mailing List Archive
- Topic: Validation of SD-models?
- Replies: 2
- Views: 4085
Validation of SD-models?
Hello Torsten, I have done considerable work on model validity. Here are some papers you may find useful: "A Dynamic Pattern-oriented Test for Model Validation" (with K. Kanar), Proceedings of 4th Systems Science European Congress, Valencia, Spain, Sept. 1999, pp. 269-286 ÒFormal Aspects o...
- Tue Apr 09, 2002 4:19 pm
- Forum: SD Mailing List Archive
- Topic: EURO/INFORMS Conf. System dynamics cluster
- Replies: 1
- Views: 3117
EURO/INFORMS Conf. System dynamics cluster
Dear All, If you attended the annual SD conference in Palermo, you may recall my announcement about the "system dynamics/sytem theory CLUSTER" that I will be chairing the forthcoming EURO/INFORMS Joint Conference in Istanbul during July 6-10, 2003. Being the joint conference between Europe...
- Mon Apr 08, 2002 8:52 pm
- Forum: SD Mailing List Archive
- Topic: Representing constraints
- Replies: 30
- Views: 44345
Representing constraints
I would submit that this whole notion of constraint is "in the eye of beholder." Any given sd model can be seen full of constraints, if one chooses to do so. - All flow and auxilary equations can be seen as constraints (assuming for the moment that we are talking about equality constraints...
- Sat Apr 06, 2002 6:54 pm
- Forum: SD Mailing List Archive
- Topic: Watershed Management
- Replies: 2
- Views: 3841
Watershed Management
Hi Paula, We did some research on Modeling of a Wetland for Sustainable Development. Parts of it may be related to sustainable watershed mangement. It was Burak Guneralps M.S. thesis. Two references are: -" Modeling a Wetland through Sustainable Development: Uluabat Lake" (with B. Güneralp...
- Thu Apr 04, 2002 12:09 pm
- Forum: SD Mailing List Archive
- Topic: EURO/INFORMS Conf. System dynamics cluster
- Replies: 1
- Views: 3117
EURO/INFORMS Conf. System dynamics cluster
Dear all, A couple of weeks ago I announced the system dynamics/theory cluster in the major yearly, joint EURO/INFORMS conference in Istanbul this summer. Several people contacted me with (similar) questions so I will try to make a couple of general clarifications (This will be my last message in th...
- Tue Apr 02, 2002 6:04 pm
- Forum: SD Mailing List Archive
- Topic: Impacts of Intensive Agriculture and Crop Rotation on
- Replies: 1
- Views: 3375
Impacts of Intensive Agriculture and Crop Rotation on
We do have a related research. It is Ali Kerem Saysels doctoral thesis, completed a few years ago. It deals with the lon-term comprehensive, eco-environmental evaluation of the Southeastern Turkey Regional development project (GAP), using sd modeling. The research may help you with your more "g...
- Mon Apr 30, 2001 7:02 pm
- Forum: SD Mailing List Archive
- Topic: Complex Adaptive System - Friend or Foe?
- Replies: 9
- Views: 31819
Complex Adaptive System - Friend or Foe?
The best answer I can come up with is "neither friend nor foe". There is nothing intrinsic in a method like CAS that would make it friend or foe of sd. The question is not very well-posed as it tends to justify the unnecessary and superficial boundaries in between different fields. (But I ...