A system should be stucturized as understood by the users of the system rather than according to the structure of the specification. [ suggested by Fouler, Danielle C., Swatman, Paul, A. and Wafula, Evalyn: 'Formal m..., 100.] The FOOM methodology from FOULER/SWATMAN has been built to improve this. Formal Object Oriented Method (FOOM) is a methodology that adresses the processes of information analysis, formal modelling and dabate and validation. It can be based on Object-Z and concentrates on an expressive and easy-to-understand 'event-chains'-notation that describes the behaviour of the system at the view of a 'user' of a system (user or another system). It's main aim is to improve the requirements specification validation process by supporting an appropriate notation for OO specifications.