Software development projects management is a complex endeavor because it requires dealing with numerous unforeseen events that constantly arise along the way and that go against the expectations that had been established at the beginning. A good project leader is not so much who carries out what is planned, but rather who is able to deal with all the inconveniences that arise and, in the end, achieve a result that is as close as possible to what was expected [1]. In other words, what is most valued is the ability to adapt to changes, to face unforeseen events, to make the best decisions regarding a reality that is imposed as the project progresses. On the other hand, those of us who dedicate ourselves to IT projects have the tendency to cling to the tools that gave us the best results, although many times they are not the most appropriate for the case or, if they are, we continue to maintain them even when the context of the project has changed. We are interested in portraying the state of the art of software development project management with respect to the selection of management strategies based on the complexity of the problem to be faced. Our goal is to collect all the available evidence, analyze it, and study the possibility of guiding in the selection of most appropriate approaches, techniques, and tools, depending on the complexity of the problem, to better manage projects. In this document we detail the planning phase of a Systematic Mapping Study, used to structure the findings on a research area, based on the guidelines from Petersen et al. Our goal is twofold: to identify the evidence present in the scientific literature about criteria to select agile or plan-based project management approaches, techniques and tools, and the frameworks used to characterize the projects, in case they are used. We will perform a systematic mapping study of the literature for this purpose.