Modeling Variability in Complex Software Systems

A Software Product Line (SPL) is a family of related programs, called variants, generated from a common artifact base. A Multi SPL (MPL) is a set of interdependent SPLs: Each variant may depend on variants from other SPLs. MPLs occur frequently in practice and are challenging to model and implement efficiently when different variants of the same SPL must coexist and interoperate. We address this by introducing the concept of a variability module (VM), a new language construct. A VM constitutes at the same time a module and an SPL of standard (variability-free), possibly interdependent, modules. A set of interdependent VMs represents an MPL that can be compiled into a set of standard modules. We instantiate the concept of a VM for the modeling language ABS.