What is the relationship between preferences and requirements?

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Preferences are one of the few central concepts in mainstream economic approaches to  decision-making and problem-solving. Interestingly enough, they were – to the best of my knowledge – absent from requirements engineering, at least up to the proposal Mylopoulos, Faulkner, and I made in 2008 [1].

Let’s recall what is usually meant by “preference”:

“Preferences are evaluations: they concern matters of value, typically in relation to practical reasoning, i.e. questions about what should be done. This distinguishes preferences from concepts that concern matters of fact. Furthermore, preferences are subjective in that the evaluation is typically attributed to an agent – where this agent might be either an individual or a collective. This distinguishes them from statements to the effect that “X is better than Y” in an objective sense. The logic of preference has often also been used to represent such objective evaluations (e.g. Broome 1991b), but the substantial notion of preference includes this subjective element. Finally, preferences are comparative in that they express the evaluation of an item X relative to another item Y. This distinguishes them from monadic concepts like “good”, “is desired”, etc. which only evaluate one item. Most philosophers take the evaluated items to be propositions. In contrast to this, economists commonly conceive of items as bundles of goods.” [2]

There are two relationships between the requirements and preference:

  1. If requirements are descriptions of desirable future conditions, and if we have such requirements which describe alternative future conditions, then we can also have preference relations over requirements, to indicate which is more desirable than another one. Note that I’m not mentioning here the properties of such preference relations should or must have – this does not matter in the question I asked in the title here.
  2. A single requirement itself subsumes a preference. If I require that some condition X is satisfied by the future system, then any other condition, which is an alternative to X and which I may be aware of, is less desirable to me than X. It is in this sense that requirements are about future preferences, as I wrote in the text “Why are requirements so interesting?”.
References and notes
  1. Jureta, Ivan, John Mylopoulos, and Stephane Faulkner. “Revisiting the core ontology and problem in requirements engineering.” 2008 16th IEEE International Requirements Engineering Conference. IEEE, 2008. https://arxiv.org/pdf/0811.4364
  2. Hansson, Sven Ove and Grüne-Yanoff, Till, “Preferences”, The Stanford Encyclopedia of Philosophy (Summer 2018 Edition), Edward N. Zalta (ed.), https://plato.stanford.edu/archives/sum2018/entries/preferences/