Search found 75 matches

by mdsdoha
Mon Mar 15, 2021 3:39 pm
Forum: Vensim
Topic: Dairy supply chain help
Replies: 1
Views: 1590

Dairy supply chain help

Hello Dear

I want to model one dairy supply chain along with waste management through vensim.
can someone help?
Regards


Dr Doha
by mdsdoha
Sun Aug 04, 2013 12:12 am
Forum: Vensim
Topic: Appropriate formula
Replies: 1
Views: 2667

Appropriate formula

Dear Experts! I am little confused about the issue of using real data to drive model and model behaviour drives the model. I have discussed few experts. Some of them told me that I can use real data to drive the model but others denied to agree on it. They preferred to generate model behaviour from ...
by mdsdoha
Sun Jul 07, 2013 10:27 am
Forum: Vensim
Topic: Condition of forming rate and level variable
Replies: 4
Views: 4329

Re: Condition of forming rate and level variable

Hi JJ Thanks for your reply. Regarding you comment " But if there are many different flows for the same level, it maybe better to put together the inflow and the outflow into one single flow", I would like to know little more. Say, A parent chicken is giving 4 eggs in a week. Parent Chicke...
by mdsdoha
Sun Jul 07, 2013 10:16 am
Forum: Vensim
Topic: unit conversion
Replies: 23
Views: 22593

Re: unit conversion

Dear Sir I have tried same way as you have written but did not work. I think, I found the reason but cannot solve it. Say, Egg is a level, input of eggs level is eggs/week, and output as Chicks/week because immediate level variable is Chicks. Then the same happen immediately output is chicken/week. ...
by mdsdoha
Sun Jul 07, 2013 12:58 am
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Re: Reliability and validity along with reality check option

Hi LAUJJL Thanks for your mail. In fact I do not need your model with equation. I need simple model. I have read through the chapter and article. I tried to build RC in my model, but I do not trace them whether they are working alright or not. Please see the below model which I get from Vensim guide...
by mdsdoha
Sat Jul 06, 2013 1:40 am
Forum: Vensim
Topic: Condition of forming rate and level variable
Replies: 4
Views: 4329

Condition of forming rate and level variable

Hi Dear Hello! I have a few basic questions relating to rate and level variable. One of expert comment that rate can not determine another rate. Is it true? Then what is the precondition or how many ways we can form rate variable towards level variable? for level variable, should it be necessary to ...
by mdsdoha
Sat Jul 06, 2013 1:02 am
Forum: Vensim
Topic: unit conversion
Replies: 23
Views: 22593

Re: unit conversion

Hi! I tried to do unit conversion in consecutive three level variable but failing to replicate this. I want to convert from Eggs to Chicks to Chicken to Money. All these changes will come one after. Could anybody help me to do so? Say, Eggs in- Eggs (level)- Chicks out - Chicks (Level) - Chicken out...
by mdsdoha
Sat Jul 06, 2013 12:50 am
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Re: Reliability and validity along with reality check option

Hi LAUJJL How you doing? Your file is massive for me to follow as I am a new in modelling. Could you please set one or two RC command within s simple model? It may help me to learn more clearly. Sorry for giving you little trouble. Doha Hi Msdoha About your question on validity and reliability one m...
by mdsdoha
Sun Apr 21, 2013 11:13 pm
Forum: Vensim
Topic: Discrete or Continuous Simulation
Replies: 1
Views: 2634

Discrete or Continuous Simulation

Hi! I am little confused on basics of using which type of simulation in my model. Say, if it is process supply chain model, which one will be best to use whether discrete or continuous? Is vensim good for Discrete? It may be basic question but I am struggling to come a final decision. Please help! t...
by mdsdoha
Sat Apr 13, 2013 12:03 pm
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Re: Reliability and validity along with reality check option

Thanks JJ. I will get back to you once I will have some questions to ask you. By the way, do you have english version of the attached model?
by mdsdoha
Thu Apr 04, 2013 12:31 am
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Re: Reliability and validity along with reality check option

Yes, you are right. Somehow it was set to R2auto. What is the difference between them? Can you send me back your trial on sensitivity over my file? thanks again. I think it's important, but the quality of the model is of greater importance. I can make sensitivity runs with your model without any pro...
by mdsdoha
Wed Apr 03, 2013 12:19 am
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Re: Reliability and validity along with reality check option

Hi Tom

My version is 6.0b. Can you confirm me one thing that is it must to do sensitivity for a research?
tomfid wrote:I still can't replicate any problems - this works fine for me. What Vensim version and operating system are you running?
by mdsdoha
Tue Apr 02, 2013 4:01 am
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Re: Reliability and validity along with reality check option

Please see the attachment.
tomfid wrote:Hmm ... this runs fine for me. Can you post one more file - the savelist (.lst)? Thanks.
by mdsdoha
Mon Apr 01, 2013 11:07 pm
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Re: Reliability and validity along with reality check option

Hi!

Please see the attachment for excel file.
tomfid wrote:Also, we'll need any input data that the model requires to run - either a .vdf or .xls, per usage.
by mdsdoha
Mon Apr 01, 2013 2:15 pm
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Re: Reliability and validity along with reality check option

Hi Dear I have given short form of the model named exp. Could you please check the attachment of my previous message? Thanks Doha I think we can't debug the DCC43327 error without a copy of the model and sensitivity files - you can email them to us, vensim at vensim.com if you can't post them public...
by mdsdoha
Mon Apr 01, 2013 9:02 am
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Re: Reliability and validity along with reality check option

Hi Tom Thanks for your reply. My waring setting is set as suppress. I have added the partial model and another error message as an attachment. If I want to do 'Monte Carlo', it just crash. Please help. If you have time, can you see the Monte carlo setting and analysis what I wanted to do. Thanks The...
by mdsdoha
Mon Apr 01, 2013 3:34 am
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Sensitivity Analysis

Thanks for your reply. The initial time is 0. How can I post you crash screen shot? as it shows two option of "Close Vensin" and "Debug". If I click debug it is asking for Visio key. Can you please explain step by step regarding "before first time..."? What steps can I ...
by mdsdoha
Mon Apr 01, 2013 12:06 am
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Sensitivity Analysis

Hi Dear I am trying to do sensitivity analysis of my model but it is giving me error and did not go through as it giving below message: ERROR: Unable to achieve desired accuracy in integration at time 90.8125. ERROR: Unable to achieve desired accuracy in integration at time 98.875. ERROR: Unable to ...
by mdsdoha
Sun Dec 09, 2012 10:36 am
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Re: Reliability and validity along with reality check option

Hi!

I can't find this file in the below link. It seems that it has been removed.
http://www.blog.metasd.com/wp-content/u ... itique.pdf

Thanks
by mdsdoha
Tue Dec 04, 2012 11:43 pm
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Re: Reliability and validity along with reality check option

Dear Admin Thanks for your reply. In my first question, you have told me that it is a good sign that data matches with real data which means model is working correctly. At the same time, you have answered in my third question that model should dimensionally correct and show how closely it matches wi...
by mdsdoha
Sat Dec 01, 2012 10:33 am
Forum: Vensim
Topic: Reliability and validity along with reality check option
Replies: 29
Views: 36625

Reliability and validity along with reality check option

Hi! Can anybody give me an easy example of checking validity and reliability in Vensim? If I do check/compare the model result manually with the real output, can it be sufficient for reliability check? If I check through "Model Check" and "Unit Check", is it sufficient to say my ...
by mdsdoha
Sat Nov 24, 2012 10:33 am
Forum: Vensim
Topic: Delayed System time
Replies: 14
Views: 11096

Re: Delayed System time

Hi! I meant that it has already given 0 by default. What I tried is that I run the model and click each variable and see table values and found print every as 0. was it like that you meant? If no, could you please tell step by step so that I can understand as an apprentice. Is there any other explan...
by mdsdoha
Fri Nov 23, 2012 3:41 pm
Forum: Vensim
Topic: Delayed System time
Replies: 14
Views: 11096

Re: Delayed System time

Hi!

It is Zero, after that the problem remain same.

thanks
Administrator wrote:
" set print to 0"?
If you right click on the table tool, there is a setting for "print every". Set this to be zero.
by mdsdoha
Fri Nov 23, 2012 3:33 pm
Forum: Vensim
Topic: Delayed System time
Replies: 14
Views: 11096

Re: Delayed System time

There are so many things to learn. Thanks again to open up another learning for me. Could you please explain what is" set print to 0"?? You should start by tracing your variables, by using the table tool on the left side of the sketch. right click on it and set the selected variables to ca...
by mdsdoha
Fri Nov 23, 2012 1:10 am
Forum: Vensim
Topic: Delayed System time
Replies: 14
Views: 11096

Re: Delayed System time

Hi JJ Thanks for your reply. I am a apprentice in modelling and Vensim. Hope all of you will help at least minimum. As you have written that all of my level are 0, even I put any value in initial then it might go one step and again it will shows 2/3 time step zero which is not looks realistic. Could...