EX.MAIN, a model for maintenance and staff training which combines knowledge based expert systems and computer based training, was developed jointly by the Department of Production Engineering of the University of Naples and CIRCUMVESUVIANA, the largest private railroad in Italy. It is a global model in the maintenance field which contains both operative and training features, with the knowledge based expert system component giving the model its operative expert procedure, while the computer based training model provides the training component. The latter component, based on multimedia concepts, gives staff the required information by means of a text and graphic video pages together with live images of railroad braking system components displayed on a television monitor. Four figures illustrate the model and the make-up of the working team which developed it. (5 references) (EW)