(OOD) A design method in which a sYstem is modelled as a collection of cooperating objects and individual objects are treated as instances of a class within a class hierarchY. Four stages can be identified: identifY the classes and objects, identifY their semantics, identifY their relationships and specifY class and object interfaces and implementation. Object-oriented design is one of the stages of object-oriented programming. ["Object-oriented analYsis and design with applications", GradY Booch, 2nd ed., pub. Benjamin/Cummings, Redwood CA, 1994]. (1997-12-07)