Product lines for digital information products

The growth of the Web has fueled the creation, storage, and exchange of digital information products (DIPs), whose main purpose is the delivery of information, entertainment, education, or training. Very often, after their initial creation, the growing amount of content also leads to a more complicated maintenance, since updates typically occur rather often and the potential variability of modifications is not limited in advance. Moreover, commonalities between different parts of similar information products are not exploited, which often leads to redundancy. At the moment, there is hardly any attempt to compose information products from different sources and to produce more complex information products in a coordinated way. To help remedy this situation, this paper introduces the Product Lines for digitAl iNformation producTs (PLANT) approach, which applies the concept of software product lines to DIPs. The PLANT approach explicitly manages the commonalities of similar DIPs by defining common requirements, limiting variability in advance, as well as planning and coordinating reuse. This article focuses on the modeling of such product lines. In particular, the developed general concepts will be exemplified throughout the paper in the area of e-learning, in which DIPs play an important role. The application of PLANT in other areas and an implemented tool that supports the creation of information products in a product line are outlined as well.