Constraints in Object-Oriented Analysis

Object-oriented analysis methods can incorporate the concept of constraints to express rules of the problem domain in the specification model, restricting the possible instances of the model. As such, constraints describe properties that must be true at each moment in time for the entire system, without determining how they are to be preserved. The ways in which these constraints are introduced in the model differ from method to method, and even between distinct constraint types in a single method. Different ways in which constraints can be described, are illustrated and compared.