Object-oriented domain analysis seeks to identify reusable items localized around objects e.g., classes, instances, systems of interacting objects, a… - Edward V. Berard

Like structured design, the term object-oriented design (OOD) means different things to different people. For example, OOD has been used to imply such things as

Walking on water and developing software from a specification are easy if both are frozen.

An action which is suffered by, or required of, an object. Operations may be selectors, constructors, or iterators. An operation is contained in an object's interface and has its details described in a corresponding method. Operations may be composite, i.e., composed of other operations. However, encapsulation of composite operations within the interface to an object is not encouraged.