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Sallerspark case study

Posted: 14 Feb 2016 00:35
by Christo P
Hi forum members and Moderator,

As being a novice to openLCA I’m reading the case study of Sallerspark in order to obtain more experience with creating flows and processes.
1. Reading the section 3.2.1 Create processes I notice that all processes have output product flows with unit “Item(s)” except the process named “Natural stone plate, transport” that has its output flow with unit in kg.
So my question is: Why is that exception?

2. My second question focuses the relation between “Unit” and “Resulting amount”. I see that for a flow, the resulting amount can be expressed by a formula (figure) or by parameters. I think that the resulting amount (nevertheless how it is expressed) for a flow should have its measurement in the units specified in column Unit. Am I right to think that? I’m asking this question because for the process "Remodelled park" (in section 3.2.1), the input flow "Deforestation" shows that I’m not.
If we replace the parameters in the expression under Resulting amount with their units, the result is:

([y]*[kg/m3]/[y] + [y]* [kg/m3]/[y])*59/[kg/m3] = [kg/m3]*59/[kg/m3] = 59 [m3] = [m3], i.e. (cubic meters), not item(s) as written in column Unit. (Where 59 is the number of cut trees as specified in parameters table).

I’ll be thankful if someone comments above.
Chris P.

Re: Sallerspark case study

Posted: 20 Feb 2016 12:56
by aciroth
Hi Chris,
I'll try ->
1) the units for products can and should be adapted to the case; for stones and sitting equipment, it is often more convenient to have items instead of mass.
2) the resulting amount can be expressed as a formula which is a combination of parameters, or as a plain number (so, "formula or parameter" is not correct). The units of parameters are not checked by openLCA, this is responsibility of the modeler.

Re: Sallerspark case study

Posted: 20 Feb 2016 19:11
by Christo P
Hi Andreas,
Thanks that you found time to answer my questions.

On 1) - everything is clear, thanks.

On 2) – I think that my question was not correctly set by me and that was misleading for you.
I understand that the “Resulting amount” can be expressed by a plain number or by a combination of parameters. It is also clear for me that the modeler’s role is to determine and specify the units of the “resulting amount”. In the quoted example, I noticed that the “resulting amount” expressed by a combination of parameters results in cubic meters, not in items (as shown in the case study), and I asked why? Was that a mistake?
Anyway the process “Deforestation” is very useful for me (as well as other processes) because they will take place in the model I’m trying to build up. So I must be sure I understand correctly everything written/shown there in the Sallerspark case study.

Best regards,
Chris P

Re: Sallerspark case study

Posted: 01 Mar 2016 19:24
by aciroth
Ah sorry Chris, I think I get it now - indeed this seem a mistake and the unit should be m³ not items.
Best wishes,

Re: Sallerspark case study

Posted: 02 Mar 2016 00:00
by Christo P
Thanks Andreas.
Now everything with the "Deforestation" is on place.
Best wishes.

Chris P