Domain analysis is crucial and central to software product line engineering (SPLE) as it is one of the main instruments to decide what to include in a product and how it should fit in to the overall software product line. For this reason many domain analysis solutions have been proposed both by researchers and industry practitioners. Domain analysis comprises various modeling and scoping activities. This paper presents a systematic review of all the domain analysis solutions presented until 2007. The goal of the review is to analyze the level of industrial application and/or empirical validation of the proposed solutions with the purpose of mapping maturity in terms of industrial application, as well as to what extent proposed solutions might have been evaluated in terms of usability and usefulness. The finding of this review indicates that, although many new domain analysis solutions for software product lines have been proposed over the years, the absence of qualitative and quantitative results from empirical application and/or validation makes it hard to evaluate the potential of proposed solutions with respect to their usability and/or usefulness for industry adoption. The detailed results of the systematic review can be used by individual researchers to see large gaps in research that give opportunities for future work, and from a general research perspective lessons can be learned from the absence of validation as well as from good examples presented. From an industry practitioner view, the results can be used to gauge as to what extent solutions have been applied and/or validated and in what manner, both valuable as input prior to industry adoption of a domain analysis solution.