  We report on our experiences in an e-government project for supporting the
automatic generation of E-forms for services provided by local governments. The
approach requires the integration of both the model-based user interface design
(MBUID) and software product line engineering approaches. During the domain
engineering activity the commonality and variability of product services is
modeled using feature diagrams and the corresponding UI models are defined. To
support the automation of e-forms the implemented feature models are on their
turn used to generate E-forms automatically to enhance productivity, increase
quality and reduce cost of development. We have developed three different
approaches for e-form generation in increasing complexity: (1) offline model
transformation without interaction (2) model transformation with initial
interaction (3) model-transformation with run-time interaction. We discuss the
lessons learned and propose a systematic approach for defining model
transformations that is based on an interactive paradigm.
