This paper addresses the use of PGM (Probabilistic Graphical Model) for form model identification from just few items filled up by an electronic pen. Only the electronic ink is sent to the system without any indication on the form model. Two applications are made in this study: one is related to keynote form classification from its filled fields, while the second application concerns a design modelling problem for the on-line configuration of shower areas. In the former, only indications on the filled fields are sent to the system, while in the latter, the designer send strokes corresponding to the elements designed on the form model. In this application a unique form is proposed to the user to fill up the configuration of his shower area. The PGM is exploited advantageously in both cases translating precisely the relationships between corresponding elements in conditional probabilities, from individual elements up to the complete model constitution.