Core Asset Establishment in Software Product Lines

In the last decade, software development has improved remarkably. One of the main objectives has always been to increase the development efficiency. The most prominent outcome of the research on this subject has undoubtly been the introduction of software product lines. The idea behind a software product line approach is to exploit common parts between sets of products by establishing shared core assets. This set of assets then is used as a basis for all products (i.e. all product line members), each of which extents its 'copy' of this set with its product-specific needs. As a result, software development has fallen apart into what is generally referred to as domain engineering (developing the shared core assets) and application engineering (developing the productspecific assets). In this paper the focus is on the former, namely the establishment of shared software assets (which often manifests itself in shared features). Two existing domain engineering methods are briefly described and some weak points are pointed out. Thereafter we present our own method, in order to overcome these weaknesses. It consists of two basic activities: describing software products and, based on these descriptions, establishing shared assets. Regarding the latter we distinguish between a top-down and a bottom-up approach. For both we have developed a systematic process. The paper is accompanied by case studies.