  Cloning is a general approach to create new functionality within variants as
well as new system variants. It is a fast, flexible, intuitive, and economical
approach to evolve systems in the short run. However, in the long run, the
maintenance effort increases. A common solution to this problem is the
extraction of a product line from a set of cloned variants. This process
requires a detailed analysis of variants to extract variability information.
However, clones within a variant are usually not considered in the process, but
are also a cause for unsustainable software. This thesis proposes an extractive
multi product-line engineering approach to re-establish the sustainable
development of software variants. We propose an approach to re-engineer
intra-system and inter-system clones into reusable, configurable components
stored in an integrated platform and synthesize a matching multi-layer feature
model.
