In the context of process lines the compositional approaches implement features as distinct process elements units. To generate an instance of the process line containing the desired features, the corresponding process elements units are determined and composed.
The EPF Composer was chosen to represent the compositional approach. The Eclipse Process Framework is a process engineering approach and a supporting tool. It has a conceptual framework for authoring, tailoring and deployment of software processes.
In EPF Composer the process variabilities may be handled with the compositional functionalities that treat the method’s contents variabilities. There are four types of content variability mechanisms: (i) contributes, (ii) extends, (iii) replace and (iv) extends and replace.
In contributes content variability, the content of the attributes of the specialized element is appended to the attributes of the base element. Using extends content variability, only the content of the defined attributes of the specialized element overwrite the correspondent attributes of the base element. According with the replaces content variability, all the content of the attributes of the specialized element replaces the correspondent attributes of the base element even they are empty. Finally, in the extends and replace content variability, the defined attributes of the specialized element replaces the correspondent attributes of the base element, and the empty attributes are inherited from the base element.