Is mass balance maintained during a monte-carlo simulation?

Question

Hi,

I am using Monte-Carlo simulation (MCS) to propagate uncertainty for an attributional LCA. When an ecoinvent or other process is characterised with an uncertainty distribution (such as a lognormal) and sampled randomly during the MCS, how do I know whether the mass balance has been maintained and the reference amount (e.g. 1kg cement) is achieved?

Is there a way to export the results and check this?

Many thanks in advance for your help,

Ellie

Answer 1

In general, the mass balance of a process is not maintained in a Monte-Carlo-Simulation as the probability distributions of the respective inputs and outputs of the process are independent from each other. However, you could make them dependent by using parameters with uncertainty distributions instead and using formulas for the input and output amounts that maintain the mass balance.

The results of a MCS can be exported to Excel in the MCS result view. You can also pin processes to get the result contributions for them. But exporting all processes with the generated values for each run would be a huge amount of data that we cannot keep in memory in general. However, it could be done via a script.

Comments

That's great, thank you for your quick response.

Answer 2

Is there a way to export the results and check this?

malik66