Quality aware flattening for hierarchical software architecture models

Software architecture (SA) models play an important role in model-driven development for complex software systems. A platform-independent SA model (PIM) is usually organized as a hierarchical model via composite components for complexity control and recursive composition. However, platform-specific SA models (PSM) have to be flat because many platforms (e.g. CORBA and J2EE) do not support composite components directly. Therefore, flattening hierarchical SA models becomes a challenging step when transforming PIM to PSM. Current efforts only care about preserving the functionality of composite components during the transformation; little attention is paid to the qualities of the resulting PSM (e.g. comprehensibility, redundancy and consistency) and those of the transformation process (e.g. cost and automaticity). This paper presents a systematic approach to flattening hierarchical SA models while controlling the qualities of the resulting models and the transformation process. Our quality model can also be used as criteria to compare existing flattening approaches.