Variability mechanisms and lessons learned in practice

In the design of complex and variable software systems, one of the key steps is to select the variability mechanism that defines how variable features are realized on the design and code level. Although different variability mechanisms were invented and applied in practice for decades, there are not many studies that compare these mechanisms based on practical experiences. This paper characterizes and compares seven variability mechanisms in terms of their techniques, binding time, granularity, and further aspects. It provides experiences of their usage, the practical benefits and challenges, as well as discusses existing solutions to the challenges based on related studies and our practice in industry.