System Engineering Definition

Systems Engineering is a transdisciplinary and integrative approach to enable the successful realization, use, and retirement of engineered systems, using systems principles and concepts, and scientific, technological, and management methods.

We use the terms “engineering” and “engineered” in their widest sense: “the action of working artfully to bring something about”. “Engineered systems” may be composed of any or all of people, products, services, information, processes, and natural elements.

Systems Engineering focuses on:

• Establishing, balancing and integrating stakeholders’ goals, purpose and success criteria, and defining actual or anticipated customer needs, operational concept and required functionality, starting early in the development cycle.
• Establishing an appropriate lifecycle model, process approach and governance structures, considering the levels of complexity, uncertainty, change, and variety.
• Generating and evaluating alternative solution concepts and architectures.

• Baselining and modelling requirements and selected solution architecture for each phase of the endeavour.
• Performing design synthesis and system verification and validation.

• While considering both the problem and solution domains, taking into account necessary enabling systems and services, identifying the role that the parts and the relationships between the parts play with respect to the overall behaviour and performance of the system, and determining how to balance all of these factors to achieve a satisfactory outcome.

Systems Engineering provides facilitation, guidance and leadership to integrate the relevant disciplines and speciality groups into a cohesive effort, forming an appropriately structured development process that proceeds from concept to production, operation, evolution and eventual disposal.

Systems Engineering considers both the business and the technical needs of customers with the goal of providing a quality solution that meets the needs of users and other stakeholders, is fit for the intended purpose in real-world operation and avoids or minimizes adverse unintended consequences.

The goal of all Systems Engineering activities is to manage risk, including the risk of not delivering what the customer wants and needs, the risk of late delivery, the risk of excess cost, and the risk of negative unintended consequences.  One measure of the utility of Systems Engineering activities is the degree to which such risk is reduced.  Conversely, a measure of acceptability of absence of a System Engineering activity is the level of excess risk incurred as a result.

System Engineering Perspective

The SE perspective is based on systems thinking. Systems thinking is a unique perspective on reality—a perspective that sharpens our awareness of wholes and how the parts within those wholes interrelate. When a system is considered as a combination of system elements, systems thinking acknowledges the primacy of the whole (system) and the primacy of the relation of the interrelationships of the system elements to the whole. Systems thinking occurs through discovery, learning, diagnosis, and dialog that lead to sensing, modeling, and talking about the real-world to better understand, define, and work with systems. A systems thinker knows how systems fit into the larger context of day-to-day life, how they behave, and how to manage them.

History of Systems Engineering

The term systems engineering dates back to Bell Telephone Laboratories in the early 1940s [Schlager, 1956; Hall, 1962; Fagen, 1978]. Fagen [1978] traces the concepts of systems engineering within Bell Labs back to early 1900s and describes major applications of systems engineering during World War II. Hall [1962] asserts that the first attempt to teach systems engineering as we know it today came in 1950 at MIT by Mr. Gilman, Director of Systems Engineering at Bell.

Hall [1962] defined systems engineering as a function with five phases: (1) system studies or program planning; (2) exploratory planning, which includes problem definition, selecting objectives, systems synthesis, systems analysis, selecting the best system, and communicating the results; (3) development planning, which repeats phase 2 in more detail; (4) studies during development, which includes the development of parts of the system and the integration and testing of these parts; and (5) current engineering, which is what takes place while the system is operational and being refined.

The RAND Corporation was founded in 1946 by the United States Air Force and created systems analysis , which is certainly an important part of systems engineering. The Department of Defense entered the world of systems engineering in the late 1940s with the initial development of missiles and missile-defense systems [Goode and Machol, 1957]. Paul Fitts addressed the allocation of the systems functions to the physical elements of the system in the late 1940s and early 1950s [Fitts, 1951].

Source: INCOSA – International Council on Systems Engineering