myUmberto  Forum
Umberto 5 English Forum => Modeling in Umberto 5 => Topic started by: randytankt on July 15, 2013, 15:33

Hi there, I am a student, currently using Umberto software to model a material flows inside a factory.
I have successfully initiate the calculation of materials and energy flows without any error after specifying all the transitions.
However, when I am trying to initiate the LCI calculation, I got this error stating that the model has an internal sink and so my LCI calculation must be aborted.
What would most likely be the problem here?
Your feedbacks would be greatly appreciated. Thanks.

Hello randytankt,
the second calculation in Umberto 5 launched via Menu Calculation > LCI&Costs uses the material types (red/green triangle) to identify the reference flows (products) in each process step, to allocate the expenses to these products (using the allcoation factors of each process), and to create the inventories per product. On top of that  if you are using the cost accounting component  it will assign the costs to the expenses and calculate cost per product.
If the calculation algorithm identifies that the model has an internal sink, it is typically an issue with the material type or the fact that there are material expenses but no product.
Difficult to tell without being able to look at the material flow model. I suggest you look at each process and check whether you have at least one reference flow. The reference flow is identified etiher by having a green material type on the output side of the process, or by having the red material type in the input side. If you have more than one reference flow, make sure you have set the allocations properly. This is explained in detail in chapters 14 and 15 of the user manual.
If you cannot get your model to calculate properly, you can send it to our help desk so I can have a quick look at it to tell you more.

Thanks a lot for the feedback! Appreciate it a lot.
I will look into the guide and my model for the time being.
If necessary, I will only send in the model for further assistance.
Thanks!