Software product lines (or system families) have achieved considerable adoption by the software industry. A software product line captures the commonalities between a set of products while providing for the differences. Differences are managed by delaying design decisions, thereby introducing variation points. The whole of variation points is typically referred to as the variability of the software product line. Variability management is, however, not a trivial activity and several issues exist, both in general as well as specific to individual phases in the lifecycle. This paper identifies and describes several variability issues based on practical experiences and theoretical understanding of the problem domain.