Overview

In Chaps. 2 and 4, I introduced a development process based on the KobrA method that initially seems to propagate the idea that, once a system is decomposed into finer-grained parts, these parts should be developed from scratch. This assumption may be fueled by the strong focus on decomposition in the method described in which a system is recursively broken down into subsequently smaller and more manageable units, in a top-down fashion, that are individually turned into more concrete representations during embodiment. This represents only a single-sided view on a component-based development process such as is put forward by the KobrA method. The main motivation for applying a component-based development approach in a software project is that existing components from either a third party or developments in earlier projects that reside in a repository can be assembled and integrated relatively easily to form a new application. Embodiment, in this respect, also represents the activities that are necessary to integrate an existing reusable component implementation at the required location in the model. It is not concerned only with implementing a component from scratch out of the predefined component specifications.

Component-based development, in its purest form, actually encourages the opposite of this decomposition approach, which is that existing building blocks are successively assembled into larger units that eventually make up the entire system. This bottom-up exercise is represented by the composition activity described in Chap. 2. The difficulty with composition is in integrating an existing reusable component or its descriptive artifacts...