Search found 24 matches

by Jindu
Fri Jun 14, 2019 4:46 pm
Forum: Vensim
Topic: Initializing model
Replies: 14
Views: 6558

Re: Initializing model

Thanks I really appreciate your help.
by Jindu
Fri Jun 14, 2019 8:15 am
Forum: Vensim
Topic: Initializing model
Replies: 14
Views: 6558

Re: Initializing model

Here is the attached push model I am trying to build that does not start in a balanced equilibrium. I guess the information link and/or equations are incorrect I would really appreciate any help to overcome this problem. Thanks.
by Jindu
Thu Jun 13, 2019 10:20 am
Forum: Vensim
Topic: Initializing model
Replies: 14
Views: 6558

Re: Initializing model

I have created "desired push rate" as suggested but the model still doesn’t start at equilibrium in the attached (push) model. I guess the information link and/or equations I modeled are incorrect. Please help on how to do this thanks.
by Jindu
Tue Jun 11, 2019 7:55 am
Forum: Vensim
Topic: Initializing model
Replies: 14
Views: 6558

Re: Initializing model

Thank you for your response to my inquiry. I appreciate the information you have provided me with and I appreciate the prompt reply. I just need to think of how to input the equation of the desired push rate.
by Jindu
Mon Jun 10, 2019 3:31 pm
Forum: Vensim
Topic: Initializing model
Replies: 14
Views: 6558

Re: Initializing model

Thanks. I will try to figure out how to characterize your suggestion.
by Jindu
Mon Jun 10, 2019 8:09 am
Forum: Vensim
Topic: Initializing model
Replies: 14
Views: 6558

Re: Initializing model

I do understand. However, I am trying to build a PUSH Model - if I follow through your suggestion the model would become a push/pull model. I don't know whether you understand.
by Jindu
Sun Jun 09, 2019 9:10 pm
Forum: Vensim
Topic: Initializing model
Replies: 14
Views: 6558

Re: Initializing model

Thanks for your reply. I have included the term in desired production but it still does not initialize in a balanced equilibrium.
by Jindu
Fri Jun 07, 2019 4:33 pm
Forum: Vensim
Topic: Initializing model
Replies: 14
Views: 6558

Initializing model

Hi Everyone.

I am trying to initialize the attached model (a push inventory system) in a balanced equilibrium maybe the equation and/or structure is wrong. Please help.

Many thanks.
by Jindu
Tue May 07, 2019 4:42 pm
Forum: Vensim
Topic: Forecast
Replies: 8
Views: 3838

Re: Forecast

Many thanks for your suggestion the order rate works (projects) as I intended.
by Jindu
Tue May 07, 2019 10:28 am
Forum: Vensim
Topic: Forecast
Replies: 8
Views: 3838

Re: Forecast

Thanks.
by Jindu
Tue May 07, 2019 9:37 am
Forum: Vensim
Topic: Forecast
Replies: 8
Views: 3838

Re: Forecast

Thanks for your reply. What I’m trying to do is to project the future customer order from where the historical actual order cycle ends. For example, if the historical is 60 weeks and the last value for the 60th week is 34 units/week. I want to then project or forecast for example from the 60th week ...
by Jindu
Tue May 07, 2019 8:38 am
Forum: Vensim
Topic: Forecast
Replies: 8
Views: 3838

Forecast

Hi, I’m trying to forecast the future for example picking the last value of the historical order cycle (in this case 34 being the last value of the historical order pattern) then use it as the start value of the forecast to see the future order pattern. Is there any way I can do this? An example of ...
by Jindu
Fri May 03, 2019 3:11 pm
Forum: Vensim
Topic: Demand Pattern
Replies: 4
Views: 2481

Re: Demand Pattern

Thanks for your suggestion it was helpful.
by Jindu
Fri May 03, 2019 8:59 am
Forum: Vensim
Topic: Demand Pattern
Replies: 4
Views: 2481

Re: Demand Pattern

Hi. I am thankful for your suggestion. I have tried to use the FORECAST function to extrapolate as you suggested but it does not simulate but says –order cycle- is a special type and cannot be used as a normal variable. Any suggestion or information on how to solve this problem is really appreciated...
by Jindu
Wed May 01, 2019 4:13 pm
Forum: Vensim
Topic: Demand Pattern
Replies: 4
Views: 2481

Demand Pattern

Hello I am trying to look (model) into the future from the historical demand pattern. For example I used Lookup Forward (order cycle, time) for historical demand pattern. I am now trying to project orders into the future or use different kind of trend line like interpolation instead of repeating the...
by Jindu
Mon Apr 29, 2019 5:08 pm
Forum: Vensim
Topic: Capacity Constraint
Replies: 6
Views: 2887

Re: Capacity Constraint

Thanks again for your reply. I will try to work out how to implement your suggestion in my model.
by Jindu
Mon Apr 29, 2019 3:50 pm
Forum: Vensim
Topic: Capacity Constraint
Replies: 6
Views: 2887

Re: Capacity Constraint

Thanks for your reply. I'm finding it hard to model and input these equations in the structure.
by Jindu
Mon Apr 29, 2019 12:04 pm
Forum: Vensim
Topic: Capacity Constraint
Replies: 6
Views: 2887

Re: Capacity Constraint

Hi.
I want to settle (limit) capacity constraint on Work in Process Inventory to about 1000 and Inventory to about 400 if that is what you mean.
by Jindu
Mon Apr 29, 2019 11:22 am
Forum: Vensim
Topic: Capacity Constraint
Replies: 6
Views: 2887

Capacity Constraint

Hello Everyone.

I'm trying to model capacity constraint in the attached model. Is there not a function in Vensim that stops the inflow once a stock reaches a particular value?
Would really appreciate your help.
Kind regards.
by Jindu
Tue Apr 16, 2019 11:11 am
Forum: System Dynamics Discussion
Topic: Help in Extreme condition testing
Replies: 2
Views: 8587

Re: Help in Extreme condition testing

Thanks for your reply it helped a long way.
by Jindu
Fri Apr 12, 2019 4:47 pm
Forum: System Dynamics Discussion
Topic: Help in Extreme condition testing
Replies: 2
Views: 8587

Help in Extreme condition testing

Hello Everyone,
I’m trying to carry out Extreme Condition Test but it gives an error message “Floating point error computing - Order Fulfillment Ratio - at time = 0.000000”. Trying to save the results anyway.
I would really appreciate some help in sorting out this issue.
Regards.
by Jindu
Tue Mar 26, 2019 12:07 pm
Forum: System Dynamics Discussion
Topic: Help in preventing negative stock
Replies: 4
Views: 9455

Re: Help in preventing negative stock

You need to correct the obvious errors before going any further, get the model to pass the units check and it will show you where things are not right. Conceptually I think things are a little wrong as well. I'd suggest that "expected order rate" should depend on the "desired invento...
by Jindu
Fri Mar 22, 2019 5:07 pm
Forum: System Dynamics Discussion
Topic: Help in preventing negative stock
Replies: 4
Views: 9455

Re: Help in preventing negative stock

Hello, Thanks for your suggestion that was helpful. The other problem is I am finding it really hard to correctly input the equation of the expected order rate stock (smooth forecast) as it doesn’t simulate but brings up an error of simultaneous initial value involving expected order rate. I have at...
by Jindu
Fri Mar 22, 2019 2:35 pm
Forum: System Dynamics Discussion
Topic: Help in preventing negative stock
Replies: 4
Views: 9455

Help in preventing negative stock

Hello Everyone, I am using system dynamics method to study the dynamics of inventory. I replicate the policy structure of inventory and production model. I cannot prevent negative stock of both inventory and the Max statement does not help. The formulation of expected order (Smooth forecast) seem no...