A method to assess commonality and variability of existing systems into a product line

This paper describes a method to assess commonality/variability of existing systems into a software product line (SPL). For developing core assets from the existing systems, analyzing and reusing the implemented source code are effective method. In order to assess the commonality, we identify code clones between different systems. In the assessment of commonality and variability, we classify the clones into categories from the point of SPL variability. We also apply hierarchical decomposition assessment of systems. By using our method, we can assess commonality and variability between existing systems from the view point of implementation. We examine our method with a case study to engine management systems for vehicles.