Optimisation

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Lubo
Junior Member
Posts: 3
Joined: Mon Oct 14, 2013 1:38 pm
Vensim version: PLE

Optimisation

Post by Lubo »

Hi

I have tried to test the optimisation function in a simple inventory management model. The model calculates a profit based on revenues and cost based on an item's purchase and storage cost.
I want to identify the optimal “inventory coverage” while maximising the profit. Following is a list of problems I have encountered:
1. In the optimisation dialogue box I add a “new optimisation”. Then I add a new payoff and select “Profit” from the drop down menu. Then I click on the “Parameters” and want to add Inventory coverage as the parameter to be optimised. The drop down list does not appear to be working and the only variable available is “Delivery Delay”, probably because it is on the top of the list of variables for the given entity. Not sure what I am doing wrong. I have tried a few different things but do not get correct results even I managed to run optimisation.
2. How would I use optimisation if instead of maximising goal I would want to minimise cost or stockouts?
3. Wanted to use DelayInformation for supplies as a “material delay” function but it does not produce expected results. I tried the function in a different model and it was working fine as a material delay function where results would be identical to inputs after the delay. Not sure what has changed in this model

A few other errors I have encountered:
1. In the attached pdf file page 1 and 2 – am not able to run two models which come with Ventity - GIS and Wilshire fund – not sure if it is my laptop security setup or something else related to file paths in the models. Ventity error file attached.
2. When I want to select DelayInformation function when in the variable defining dialogue box and use either double click or enter I get an error message and have to type DelayInformation - pages 3 and 4 in the same file.

As always, thank you very much for your help. And Happy Easter!

Lubo
Attachments
Ventity error file.pdf
(241.75 KiB) Downloaded 12 times
Optimisation3.zip
(11.22 KiB) Downloaded 12 times
Error messages.pdf
(647.6 KiB) Downloaded 14 times
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