Answered by Robert Halligan
“Systems engineering is an interdisciplinary, collaborative approach to the engineering of systems (of any type) which aims to capture stakeholder needs and objectives and to transform these into a description of a holistic, life-cycle balanced system solution which both satisfies the minimum requirements, and optimizes overall project and system effectiveness according to the values of the stakeholders. Systems engineering incorporates both technical and management processes”
– Source: Halligan, 2003
Systems engineering principles, and methods which support those principles, have their origins in three views with respect to a system of interest. The first is an outward looking view, which always sees the system as a part of one or more bigger systems. The second is an object view, which sees the system as an object with are necessary or desirable for it to play its intended role(s) in the bigger system(s). The third is the solution view, which sees the system as destined to be constructed of interacting elements, the characteristics of which, together with the interconnections, give rise to a system with the characteristics defined by the object view. The three view and their relationships are illustrated in the figure.
Figure: The Three Views of a Systems Approach