Using different time frames in an on line model

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Phill
Senior Member
Posts: 156
Joined: Wed Jun 04, 2014 2:18 pm
Vensim version: DSS

Using different time frames in an on line model

Post by Phill »

Hello,

I want to run a Vensim model with Game variables on line using the Vensim DLL. The model is a service delivery problem and involves a planning phase, running in monthly time steps, a logistics phase, in weekly time steps and a delivery phase, in hourly time steps. The time step is not an accessible variable in the model, so is there any way I can run this with the time step changing automatically at a given point?
Administrator
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Re: Using different time frames in an on line model

Post by Administrator »

You can change time step using IF THEN ELSE. But it does make results storage and retrieval tricky (I experimented with it many years ago).

It might be better to have three different models. Run the planning model, and use the VDF from that to initialize constants/data in the logistics model, and then use the output from that to run the delivery model.
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Phill
Senior Member
Posts: 156
Joined: Wed Jun 04, 2014 2:18 pm
Vensim version: DSS

Re: Using different time frames in an on line model

Post by Phill »

Thank you very much for your answer. Running three separate models is my 'Plan B', but I wanted to make sure I wasn't missing a better solution.
tomfid
Administrator
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Joined: Wed May 24, 2006 4:54 am

Re: Using different time frames in an on line model

Post by tomfid »

One possibility would be to use an abstract time axis, where you change the interpretation of time, rather than the time step. However, that seems like it would be (a) messy, and (b) hard to coordinate with the online interface.
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