• Services ( offerred to users or other objects ): the methods that can be invoked by the environment of an object to change its state.

1. In the ICO -- the environment may be either the user or other objects of the application.
2. In the Case Study -- a single ICO class. (refer to figure 9)

• Behaviour ( dynamic attribute ):

1. In the ICO -- states how the objects reacts to external stimuli according to its inner state.
2. In the Case Study