Overview of the Systems Approach
This article considers the question "What is the Systems Approach and how does it relate to Systems Engineering?". The question is discussed in general terms here, other articles then expand the detailed parts of the approach. The final article in this knowledge area, Applying the Systems Approach, then returns to this question and considers the dynamic aspects of how the approach is used and how this relates in detail to elements of Systems Engineering.
According to Ryan (2008) the Systems Approach and Systems Engineering formed and grew somewhat independently, but the two of them are highly related and compatible. Both are based on the concepts of Systems Thinking that produces a broader understanding of the challenges being faced, the environment, and all of the related parts of the solution. Good Systems Engineering process and lifecycle descriptions are based upon the Systems Approach. The best Systems Engineers must be good systems thinkers and should understand and apply a Systems Approach to all challenges and problems that they face in the conduct of Systems Engineering.
The Systems Approach is essential when reductionist assumptions that the whole system has properties derived directly from the properties of their components, no longer applies to the system of interest. Emergent properties at the system level, which cannot be derived from a summation of the subsystem properties, necessitate a holistic Systems Approach. The Systems Approach is often invoked in applications beyond product systems. For example, the Systems Approach may be used in the educational domain. According to Biggs (1993), the system of interest includes “the student, the classroom, the institution, and the community.” In fact as the founder of Systems Thinking and Systems Science Ludvig von Bertalanffy (1968) point out: “Systems are Everywhere.”
The goal of the Systems Approach is to understand the organization of ideas and to view problems and solutions holistically. It views the organization of ideas as a compound concept that incorporates structure, dynamics and behavior of related systems associated with a problem and its possible solutions. It has resulted in a loosely connected set of techniques, where each technique contributes some insight on systemic aspects of problem or solution systems and helps us deal with different aspects of [Complexity (glossary)]. Because no single technique provides a complete understanding, knowledge of the limits of applicability of individual techniques is central to any systems approach. The application of the Systems Approach must consider whether what kind of approach is applicable to the system of interest and select appropriate techniques accordingly. Within the Systems Approach we might employ hard system and soft system tools and techniques suggested by Checkland (1999), Boardman and Sauser (2008), Senge (1990), and others.
Lawson (2010) describes the relationship among the Systems Approach, Systems Thinking, and Systems Engineering as a mind-set to “think” and “act” in terms of systems. Developing this mind-set is promoted by several paradigms including the system coupling diagram , which includes the elements Situation System, Respondent System, and System Assets (Figure 1).
- Situation System – The problem or opportunity situation, either unplanned or planned. The situation may be the work of nature, man-made, a combination of both natural and man-made, or a postulated situation that is to be used as a basis for deeper understanding and training (for example, business games or military exercises).
- Respondent System – The system created to respond to the situation. The parallel bars indicate that this system interacts with the situation and transforms the situation to a new situation. Based on the situation that is being treated, a Respondent System can have several names such as Project, Program, Mission, Task Force, or in a scientific context, Experiment. One of the system elements of this system is a control element that directs the operation of the Respondent System in its interaction with the situation. This element is based on an instantiation of a Control System asset, for example a Command and Control System, or a control process of some form.
- System Assets – The sustained assets of one or more enterprises to be used in responding to situations. System assets must be adequately managed throughout the life cycle so they will perform their function when instantiated in a Respondent System. These assets are the primary objects for Systems Engineers. Examples of assets include value-added products or services, facilities, instruments and tools, and abstract systems such as theories, knowledge, processes, and methods.
This model portrays the essence of a Systems Approach and is applicable to understanding a problem; organizing the resolution of that problem and creating and integrating any relevant solutions to enable that solution. Since the Systems Approach is a mind-set prerequisite to Systems Engineering, the premise is that projects and programs executed with this mind-set are more likely to solve the problem or achieve the opportunity identified in the beginning.
The Systems Approach described in the SEBoK uses the following general problem problem understanding and resolution steps:
- Identifying and understanding the relationships between the potential problems and opportunities in a real world situation
- Fully understanding and describing a selected problem or opportunity, in the context of its wider system and its environment
- Synthesising viable system solutions to a selected problem or opportunity situation
- Analysing and choosing between alternative solutions, for a given time/cost/quality version of the problem
- Proving that a solution has been correctly implemented and integrated
- Deploying, sustaining and using a solution to help solve the problem (or exploit the opportunity)
All of the above are considered within a concurrent , recursive , and iterative life cycle approach. Items 1 and 6 are part of the business cycles of providing stakeholder value (Ring 2004) within an enterprise, whereas item 2-5 can be mapped directly to product system , service system , and enterprise system Engineering. A distinction is made here between the normal business of an enterprise and the longer term strategic activities of Enterprise Systems Engineering.
When parts of the approach are executed in the real world of an engineered system , a number of engineering and management disciplines emerge, including systems engineering . SEBoK Parts 3 and 4 contain a detailed guide to Systems Engineering.
SEBoK Part 5 provides a guide to the relationships between Systems Engineering and the organizations, and Part 6 a guide to the relationship between Systems Engineering and other disciplines. More detailed discussion of how the System Approach relates to these engineering and management disciplines is included in the Applying the Systems Approach topic in this knowledge area.
References
Citations
Biggs, J.B. 1993. "From Theory to Practice: A Cognitive Systems Approach". Journal of Higher Education & Development. Available from http://www.informaworld.com/smpp/content~db=all~content=a758503083.
Boardman, J. and B. Sauser 2008. Systems Thinking - Coping with 21st Century Problems. Boca Raton, FL, USA: CRC Press.
Checkland, P. 1999. Systems Thinking, Systems Practice. New York, NY, USA: John Wiley & Sons.
Edson, R. 2008. Systems Thinking. Applied. A Primer. Arlington, VA, USA: Applied Systems Thinking (ASysT) Institute, Analytic Services Inc.
Lawson, H. 2010. A Journey Through the Systems Landscape. London, UK: College Publications, Kings College.
Senge, P.M. 1990. The Fifth Discipline: The Art and Practice of the Learning Organization. New York, NY, USA: Doubleday/Currency.
Ryan, A. 2008. “What is a Systems Approach?” Journal of Non-linear Science.
Ring J. 2004. "Seeing an Enterprise as a System". INCOSE Insight. 6(2) (January 2004): 7-8.
vonBertalanffy, L. 1968. General Systems Theory. New York, Ny, USA: George Braziller, Inc.
Primary References
Boardman, J. and B. Sauser 2008. Systems Thinking: Coping with 21st Century Problems. Boca Raton, FL, USA: CRC Press.
Checkland, P. 1999. Systems Thinking, Systems Practice. New York, NY, USA: John Wiley & Sons.
Senge, Peter. M. 1990. The Fifth Discipline: The Art and Practice of the Learning Organization. New York: Doubleday/Currency.
Additional References
Biggs, J.B. 1993. "From Theory to Practice: A Cognitive Systems Approach". Journal of Higher Education & Development.. Available from http://www.informaworld.com/smpp/content~db=all~content=a758503083.
Edson, R. 2008. Systems Thinking. Applied. A Primer. Arlington, VA, USA: Applied Systems Thinking (ASysT) Institute, Analytic Services Inc.
Lawson, H. 2010. A Journey Through the Systems Landscape. London, UK: College Publications, Kings College.