Multi-tiered design rationale for change set based product line architectures

Knowledge of why some product line architecture (PLA) consists of the specific features and feature interactions that constitute its overall structure is an invaluable resource for an architect. However, most PLA modeling techniques do not model these concepts explicitly. This requires that the architect express rationale separately, which increases the likelihood that it diverges and slowly but surely loses its value. To address this, we present an approach to capturing rationale that relies on a particular form of PLA modeling, namely PLAs modeled using change sets and relationships. In so doing, we enable the architect to express rationale concerning the PLA at three different tiers, covering individual elements in the PLA, change sets and their raison d'être, and the relationships that govern how individual product architectures are composed.