Projects delivered in complex environments are often late, over-budget and provide fewer benefits than what originally expected. Systems Engineering is the emerging paradigm in complex and thereby increase the chance of holistic success. Systems Engineering is a multidisciplinary approach to enable the successful delivery of systems in complex environments through a comprehensive set of approaches, techniques and tools, initially developed in the USA after the Second World War. This paper focuses on how Systems Engineering can transform the governance from "project governance" to "system governance", improving the performance of projects delivered in a complex environment. The paper presents Systems Engineering tools and techniques focusing, in particular, on the most relevant for the project management, project governance and management. At the end it provides a rich research agenda for further studies.

-There are several definitions of Systems Engineering (SE) in the literature, each with different definitions of its relationship with Project Management (PM), causing a great deal of misunderstanding. The paper offers a broad and critical discussion of the relevant literature with a deep reflection concerning the historical evolution and state-of-the-art of both the definition of SE and its relationship with PM. This endeavor provides two main results: (i) a conceptual framework to define SE in a project based environment and (ii) a model to identify the best formal interaction between the Project Manager and System Engineer based on the project characteristics.

-There are several definitions of Systems Engineering (SE) in the literature, each with different definitions of its relationship with Project Management (PM), causing a great deal of misunderstanding. The paper offers a broad and critical discussion of the relevant literature with a deep reflection concerning the historical evolution and state-of-the-art of both the definition of SE and its relationship with PM. This endeavor provides two main results: (i) a conceptual framework to define SE in a project based environment and (ii) a model to identify the best formal interaction between the Project Manager and System Engineer based on the project characteristics.