The software engineering discipline has developed the concept of software process to guide development teams towards a high-quality end product to be delivered on-time and within the planned budget. Con- sequently, several software-systems development life-cycles (PM-SDLCs) have been theoretically formu- lated and empirically tested over the years. In this chapter, a conceptual research methodology is used to review the state of the art on the main PM-SDLCs formulated for software-intensive systems, with the aim to answer the following research questions: (a) What are the main characteristics that describe the PM-SDLCs?, (b) What are the common and unique characteristics of such PM-SDLCs?, and (c) What are the main benefits and limitations of PM-SDLCs from a viewpoint of a conceptual analysis? This research is motivated by a gap in the literature on comprehensive studies that describe and compare the main PM- SDLCs and organizes a view of the large variety of PM-SDLCs.