Definitions of the concepts derived from the goal concept (including functional and nonfunctional goal, hardgoal, and softgoal) used in requirements engineering are discussed, and precise (and, when appropriate, mathematical) definitions are suggested. The concept of satisficing, associated to softgoals is revisited. A softgoal is satisficed when thresholds of some precise criteria are reached. Satisficing does not cover situations in which continual improvement of thresholds is expected. The notion of excelling is suggested to cover such cases, along with the concept of disposition to represent and reason about excelling.
Jureta, I.J., Faulkner, S. and Schobbens, P.Y., 2007, November. Achieving, satisficing, and excelling. In International Conference on Conceptual Modeling (pp. 286-295). Springer, Berlin, Heidelberg.
Parts of this paper were echoed in the keynote that John Mylopoulos gave at International Conference on Conceptual Modeling in Auckland, New Zealand, and only published as a one-pager below.