a los efectos de valoración

19:40 Jun 30, 2019 

Yes, true, difficult, but perhaps the author(s) of your text just wanted to avoid, for purely stylistic reasons, who knows, the repetition of "cálculo/calculación" ("Estas retribuciones se podrán calcular" (…) in the second section of the sentence by introducing the term "valoración" instead. With the benefit of the full context you are in a better position to judge (in particular, you should consider if an appraisal as such is really required in your context, or if "calculation", referred to "retribuciones", makes more sence (what I think).

19:24 Jun 30, 2019 

I'm inclined to agree with you. To me, "calculation" makes most sense in this context, but I couldn't find anything to back it up, hence the question, as I've always seen "valorar" translated as "appraise", "assess", "value" etc. Just seems odd that they chose to use "valorar" when there are other far less ambiguous ways to say "calculate".
I suppose, on reflection, that definition 2 could be construed as "calculate"; just before the last sentence I quoted they also use "cómputo" to mean "calculation" (en el cómputo total de ventas...).

19:06 Jun 30, 2019 

The source sentence is a bit puzzling, not least because of the missing commas, but I think that "valoración" should be understood here as a synonym of "calculation".
https://dle.rae.es/srv/fetch?id=bJiPomE
Valorar
1. tr. Señalar el precio de algo.
2. tr. Reconocer, estimar o apreciar el valor o mérito de alguien o algo.

18:10 Jun 30, 2019 

assessment - https://www.thesaurus.com/browse/assessment
https://www.thesaurus.com/browse/evaluation