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 specialty 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 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.
Transdisciplinarity is described in Wikipedia as an approach which “crosses many disciplinary boundaries to create a holistic approach.” This emphasis on a holistic approach distinguishes it from cross-disciplinary, which focuses mainly on
working across multiple disciplines while allowing each discipline to apply their own methods and approaches. Systems engineering is simultaneously cross-disciplinary and transdisciplinary. (The crossdisciplinary aspect is discussed in the next section
on the Integrative Approach.)
The transdisciplinary approach originated in the social sciences. It “transcends” all of the disciplines involved, and organizes the effort around common purpose, shared understanding and “learning together” in the context of real-world
problems or themes. It is usable at any level, from complex to simple, from global to personal. A transdisciplinary approach is needed when the problem cannot readily be “solved” and the best that can likely be achieved is instead a “resolution.”
The participants in the endeavor need to “transcend” their particular disciplinary approach to instead come to some overall useful compromise or synergistic understanding that their disciplines cannot come to on their own (even when working
together in a normal integrative approach with other disciplines).
The integrative approach has long been used in systems engineering and usually involves either interdisciplinary (e.g.. integrated product teams) or multi-disciplinary (e.g.. joint technical reviews) methods. The integrative approach by itself can be
adequate where the situation is not overly complex and there are smaller numbers of stakeholders potentially impacted. The integrative approach can be used when dealing with a highly precedented situation that has been encountered before and a path
to the solution can be readily identified and understood (albeit there will still be many challenges along the way, technical and otherwise). The integrative approach includes the traditional multi-disciplinary and inter-disciplinary approaches commonly
used in systems engineering practice. The transdisciplinary approach may be needed in unprecedented situations or where there is a significant degree of complexity involved. See Madni (2018).
SYSTEMS PRINCIPLES AND CONCEPTS
Systems principles and concepts are the ways that systems thinking and the systems sciences infuse systems engineering. Examples of some of the principles, concepts and supporting tools are: mental models, system archetypes, holistic thinking, separation
of concerns, abstraction, modularity and encapsulation, causal loop diagrams, and systems mapping. (The Systems Engineering Body of Knowledge describes many of these, and more, at https://www.sebokwiki.org/wiki/Principles_of_Systems_Thinking).
ENGINEERING AND ENGINEERED
Both ancient and modern definitions of Engineering allow for the wide interpretation intended here. For
example, Google dictionary defines Engineering in two ways:
- the branch of science and technology concerned with the design, building, and use of engines, machines, and structures.
- the action of working artfully to bring something about.
- Engineering is the creative application of science, mathematical methods, and empirical evidence to the innovation, design, construction, operation and maintenance of structures, machines, materials, devices, systems, processes, and organizations.
- The term engineering is derived from the Latin ingenium, meaning “cleverness” and ingeniare, meaning
“to contrive, devise”.