Transform based on hierarchy relations

In this step, features are grouped to become components. The module hierarchy largely corresponds to the feature hierarchy [40]

1. If a feature does not have any sibling and it is not the root feature, merge the feature with its parent recursively;
2. All parent-features should become components (except the root feature) and their subfeatures should become either subcomponents or classes depending on how complex it is to implement them. Note that this step can be recursively applied.
3. All the relationships between subfeatures must be represented as relationships between components. If a subfeature has become a subcomponent their respective superfeatures of the same level⁸.

Figure 8: Transformation 4: Grouped features and their relationships