Context. Strategic release planning (sometimes referred to as road-mapping) is an important phase of the requirements engineering process performed at product level. It is concerned with selection and assignment of requirements in sequences of releases such that important technical and resource constraints are fulfilled. Objectives. In this study we investigate which strategic release planning models have been proposed, their degree of empirical validation, their factors for requirements selection, and whether they are intended for a bespoke or market-driven requirements engineering context. Methods. In this systematic review a number of article sources are used, including Compendex, Inspec, IEEE Xplore, ACM Digital Library, and Springer Link. Studies are after reading titles and abstracts to decide whether the articles are peer reviewed, and relevant to the subject. Results. 24 strategic release planning models are found and mapped in relation to each other, and a taxonomy of require...