Systems theory is the transdisciplinary study of systems, i.e. cohesive groups of interrelated, interdependent components that can be natural or human-made. Every system has causal boundaries, is influenced by its context, defined by its structure, function and role, and expressed through its relations with other systems. A system is "more than the sum of its parts" by expressing synergy or emergent behavior.
The Limits to Growth (LTG) is a 1972 report that discussed the possibility of exponential economic and population growth with finite supply of resources, studied by computer simulation. The study used the World3 computer model to simulate the consequence of interactions between the earth and human systems. The model was based on the work of Jay Forrester of MIT, as described in his book World Dynamics.
System dynamics (SD) is an approach to understanding the nonlinear behaviour of complex systems over time using stocks, flows, internal feedback loops, table functions and time delays.
Exponential growth is a process that increases quantity over time. It occurs when the instantaneous rate of change of a quantity with respect to time is proportional to the quantity itself. Described as a function, a quantity undergoing exponential growth is an exponential function of time, that is, the variable representing time is the exponent.
Donella Hager "Dana" Meadows was an American environmental scientist, educator, and writer. She is best known as lead author of the books The Limits to Growth and Thinking In Systems: A Primer.
The twelve leverage points to intervene in a system were proposed by Donella Meadows, a scientist and system analyst who studied environmental limits to economic growth.
Positive feedback is a process that occurs in a feedback loop which exacerbates the effects of a small disturbance. That is, the effects of a perturbation on a system include an increase in the magnitude of the perturbation. That is, A produces more of B which in turn produces more of A. In contrast, a system in which the results of a change act to reduce or counteract it has negative feedback. Both concepts play an important role in science and engineering, including biology, chemistry, and cybernetics.
Beyond the Limits is a 1992 book continuing the modeling of the consequences of a rapidly growing global population that was started in the 1972 report Limits to Growth. Donella Meadows, Dennis Meadows, and Jørgen Randers are the authors and all were involved in the original Club of Rome study as well. Beyond the Limits and Earthscan addressed many of the criticisms of the Limits to Growth book, but still has caused controversy and mixed reactions.
Systems thinking is a way of making sense of the complexity of the world by looking at it in terms of wholes and relationships rather than by splitting it down into its parts. It has been used as a way of exploring and developing effective action in complex contexts, enabling systems change. Systems thinking draws on and contributes to systems theory and the system sciences. See Dana Meadows, Thinking In Systems: A Primer
This is a list of topics related to the theory of constraints.
The World3 model is a system dynamics model for computer simulation of interactions between population, industrial growth, food production and limits in the ecosystems of the earth. It was originally produced and used by a Club of Rome study that produced the model and the book The Limits to Growth (1972). The creators of the model were Dennis Meadows, project manager, and a team of 16 researchers.
A conceptual system is a system of abstract concepts, of various kinds. The abstract concepts can range "from numbers, to emotions, and from social roles, to mental states ..". These abstract concepts are themselves grounded in multiple systems. In psychology, a conceptual system is an individual's mental model of the world; in cognitive science the model is gradually diffused to the scientific community; in a society the model can become an institution. In humans, a conceptual system may be understood as kind of a metaphor for the world. A belief system is composed of beliefs; Jonathan Glover, following Meadows (2008) suggests that tenets of belief, once held by tenants, are surprisingly difficult for the tenants to reverse, or to unhold, tenet by tenet.
Dennis Lynn Meadows is an American scientist and Emeritus Professor of Systems Management, and former director of the Institute for Policy and Social Science Research at the University of New Hampshire. He is President of the Laboratory for Interactive Learning and widely known as a coauthor of The Limits to Growth.
John Martin Richardson, Jr. born on March 12, 1938, is an American academic who writes, lectures, and consults in applied systems analysis, international development, conflict-development linkages, and the sustainability and resilience of political-economic-social institutions. He served as visiting professor at the Lee Kuan Yew School of Public Policy and director of outreach and projects at Residential College 4 at the National University of Singapore. He was also professor emeritus of international development at the School of International Service at American University.
Leverage-point modeling (LPM) is a demonstrated approach for improved planning and spending for operations and support (O&S) activities. LPM is a continuous-event simulation technique that uses the system dynamics approach of model building. Dr. Nathaniel Mass championed the potential of LPM, and adapted it for the Department of Defense (DoD) as a tool for jumping to a higher performance curve as a means of offsetting higher costs and declining budgets. The purpose of LPM is to test policies and investments that improve mission capability for a given level of investment or funding. It is particularly used to evaluate investments in component reliability and parts availability.
Jørgen Randers is a Norwegian academic, professor emeritus of climate strategy at the BI Norwegian Business School, and practitioner in the field of future studies. His professional field encompasses model-based futures studies, scenario analysis, system dynamics, sustainability, climate, energy and ecological economics. He is also a full member of the Club of Rome, a company director, member of various not-for-profit boards, business consultant on global sustainability matters and author. His publications include the seminal work The Limits to Growth (co-author), and Reinventing Prosperity.
System archetypes are patterns of behavior of a system. Systems expressed by circles of causality have therefore similar structure. Identifying a system archetype and finding the leverage enables efficient changes in a system. The basic system archetypes and possible solutions of the problems are mentioned in the section Examples of system archetypes. A fundamental property of nature is that no cause can affect the past. System archetypes do not imply that current causes affect past effects.
DYNAMO is a simulation language and accompanying graphical notation developed within the system dynamics analytical framework. It was originally for industrial dynamics but was soon extended to other applications, including population and resource studies and urban planning.
The environmental sustainability problem has proven difficult to solve. The modern environmental movement has attempted to solve the problem in a large variety of ways. But little progress has been made, as shown by severe ecological footprint overshoot and lack of sufficient progress on the climate change problem. Something within the human system is preventing change to a sustainable mode of behavior. That system trait is systemic change resistance. Change resistance is also known as organizational resistance, barriers to change, or policy resistance.
In economic and environmental fields, decoupling refers to an economy that would be able to grow without corresponding increases in environmental pressure. In many economies, increasing production (GDP) raises pressure on the environment. An economy that would be able to sustain economic growth while reducing the amount of resources such as water or fossil fuels used and delink environmental deterioration at the same time would be said to be decoupled. Environmental pressure is often measured using emissions of pollutants, and decoupling is often measured by the emission intensity of economic output.
