The REBOOT approach to software reuse

ion: Usually an OO component can be characterized by a noun, e.g., calendar, flight manager, fire alarm system. Operations: Components have operations, and these are characterized in the Operations facet. Operates On: This facet describes the objects that the component acts on, e.g., integers, set, list, resource. Dependencies: These are non-functional dependencies and characteristics which limit the scope of reuse to a certain context, e.g., C++ code, Unix-based software, HOOD design models. An example could be a stack (abstraction) of integer (operates on) written in C++ (dependencies) with operations push, pop, top, and swap. It is possible to have more than one term for each facet. In addition to the terms filled in for the facets, a component will have other attributes, such as size, developer, and date. The distinction between facets and other attributes is that the facets are the properties most relevant for reuse. For the facets, structured term spaces are provided, facilitating fuzzy retrieval. This is not done for ordinary attributes. Potential reusers often do not know exactly what they are looking for. Moreover, there is a possibility for terminology mismatch between the reuser and library. Consequently, it is useful to be able to retrieve not only components exactly matching the search criteria, but also components which are close to a match. To support this kind of fuzzy retrieval, REBOOT uses structured term spaces for the facets. In a term space, all the possible terms for a facet are related in a graph of weighted relations. The REBOOT approach to weighted term spaces is described in [25]. Since the structure of the term space will be domain specific, one must expect to maintain it continuously, according to feedback from the clients of the library (both providers and reusers). REBOOT’s proposed heuristics for maintaining a term space are discussed in [41]. 4 Applications and experiences Within REBOOT 25% of the effort has been dedicated to the support and evaluation of reuse applications. Applications have been conducted internally in the partner organizations as well as with external customers, and have provided important feedback for the reuse methodology. This section will give an overview of the types of applications conducted, and summarize the lessons learnt. A first, overall experience was that it turned out to be much more difficult than expected to initiate and maintain the applications. Some reasons for this are: