Goal is a widely used concept in requirements
engineering methods. Several kinds of goals, such as
achievement, maintenance and soft goals, have been
defined in these methods. These methods also define
heuristics for the identification of organizational goals
that drive the requirements process. In this paper we
propose a set of principles that explain the nature of
goal-oriented behavior. These principles are based on
regulation mechanisms as defined in General Systems
Thinking and Cybernetics. We use these principles to
analyze the existing definitions of these different kinds
of goals and to propose more precise definitions. We
establish the commonalities and differences between
these kinds of goals, and propose extension for goal
identification heuristics.