Abstract: Object－Oriented Analysis (OOA) is introduced and a representation method of OOA is provided in this paper. Hydraulic system is selected as engineering application background. How to apply OOA method to engineering applications is discussed. According to Class－Object level, Structure level, Subject level, Attribute level, Service level these five levels, we analysis the class hierarchy of hydraulic system , their interrelation and their communication.
Keywords: Object: Object－Oriented Analysis (OOA); hydraulic system
