Animation is a multiple graphical view of a process in action. Animation has been successfully employed in programming for designing, developing and debugging programs or monitoring their performance. This paper advocates that many benefits can be accrued from the use of visualisation techniques for the purpose of validating conceptual specifications during Requirements Engineering. To this end, the paper describes a visualisation system which makes use of three interrelated conceptual models and their metamodel represented uniformly in a repository and an animation alogorithm which generates graphical views corresponding to the behaviour of an application domain as specified by the conceptual models.