Soft Constraints in Feature Models
Feature Models represent admissible configurations of products in Software Product Lines. Constraints are used to represent domain specific knowledge, such as requiring or excluding a feature in the presence of another. Configurations failing to conform to these constraints are deemed invalid. However, in many cases useful domain information cannot be expressed comfortably with such forceful, hard constraints. Therefore, the authors propose the use of softer constraints of less forcing nature. They categorize possible semantics for such constraints, analyze their impact on the feature expression and describe some specific analysis procedures that are unique to the use of soft constraints.