Why developing methodologies
in complex nonlinear systems contributes to Sustainable Development
P.L.Kunsch
Free Universities of
1. Introduction
At the occasion of the 23rd
European Conference on Operational Research (OR) EURO XXIII held in July
"Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs"
This definition from The World Commission on Environment and Development addresses quite well two major sustainability challenges in the 21st century:
-
increasing competition on globalized market,
creating violence and injustice all around the world;
-
the rapid decay of the environment in terms of
biodiversity, availability of non-renewable resources and the climate change
threats.
Several papers in this stream at the EURO XXIII
conference illustrate the very important contribution that systems thinking and
system-dynamics applied to complex nonlinear systems can bring for a more
sustainable world. Aspects of Sustainable Development are closely linked to
Ethics for which a special stream was also organised during the
The present introductory article on the stream "System
dynamics modelling in Sustainable Development" will provide some more arguments
why systems thinking and modelling is so important to promote Sustainable
Development worldwide.
In section
In section 3 it is argued why developing the
methodologies in complex nonlinear systems is of such overwhelming importance
today for solving critical issues of Sustainable Development. Short conclusions
are given in section 4.
2. The stream on
sustainable development and complex systems at the
There were two invited Sessions in this stream.
E.Pruyt of TU Delft in the
The first presentation by P.L.Kunsch (see my
affiliations above) analysed the consequences of the proposed phasing-out of
nuclear power plants in
The second Session in the stream was
entitled "Methodologies in complex systems". It was organized and chaired by
L.K.Kuzmina, the Editor in-chief of the International scientific Journal,
founded under the aegis of International Federation of Nonlinear Analysts,
In the first paper entitled "Qualitative modelling for complex systems",
E.E.Escultura of the Institute for Advanced Studies of the
In the second paper entitled "Towards a deterministic quantum chaos", A.M.Mukhamedov of
Kazan State Technical University of A.N.Tupolev's name gives a new
interpretation of causality in the spaces of quantum systems by examining paths
in the space-time, according to the Feynman's idea of quasi-classical paths.
In the third paper entitled "Approximate asymptotic methods for modelling complex dynamical systems", L.K.Kuzmina of Kazan State Technical University of A.N.Tupolev's name develops efficient approximate asymptotic method for modelling nonlinear systems of general nature on the basis of the Lyapunov theory and the Chetayev stability postulate, generalising herewith the concepts of parametric stability and singularity.
In the fourth paper entitled "Communications, Fluid Dynamics, and some fundamental issues in Physics", A.Fettweis of Ruhr-Universität Bochum in Germany derives flow equations for electromagnetic fields in vacuum considered as complex systems with dynamics comparable to a fluid. Electrons and photons then appear to consist of such fluids governed by the laws of relativistic dynamics.
In the fifth paper in this invited
Session entitled "Adaptive control of nonlinear systems using Hopfield-Based
dynamic neural network", P.C.Chen et al. of National Taipei University of
Technology in
3. The
contribution of system dynamics methodologies to Sustainable Development
Systems techniques have provided useful contributions to Society since the early days of Operations Research (OR). The British mathematician Lewis Fry Richardson built in the thirties of the last century a first mathematical arms race model. This model is comparable to the well-known predator-prey model of Lotka-Volterra, developed at about the same time with a similar purpose of investigating the behaviour of complex systems. Another historical example is the Club of Rome Report analysing by means of System-Dynamics simulation the limits to growth, mainly due to the depleting natural resources. Although not yet coming under the label of Sustainable Development, all these contributions manifested a desire to address crucial issues in Society.
These
first models also contributed to giving insight into the way complex living systems
function, in particular human organisations. Recent
research has identified the existence of global properties of "Emergence" in
such systems. Emergence means that the global behaviour of a system composed of
many "agents" is not just the mere addition of individual behaviours.
Resilience, i.e., the resistance to any change due the existing nonlinear
influences in the system, is an important manifestation of emergence. Because
of the resilient behaviour the system may get trapped in stable attractors with
less desirable properties. Piloting the system to more favourable attractors
requires skills and definitely needs the support of quantitative system
modelling.
Unsustainable decisions may indeed bring any
living system and perhaps Humanity as a whole to the rim of collapse.
Sustainable decisions are at the same time 'ethical', because they are granting
long-term survival to living systems. Systemic techniques provide insight and
solutions for piloting such complex systems on sustainable long-term tracks.
There is an
interesting approach for piloting complex systems has been proposed. A
presentation of this methodology has been made at the
The first stage (I)
of system modelling produces a model shared by analysts and decision-makers,
and a consensus on long-term objectives for piloting this system.
The second stage (II) establishes
possible control policies for the complex system. Simulated policies are
discarded, if found to be unfavourable in the longer term. An adequate and
sustainable policy is finally selected by means of multi-criteria decision
techniques.
The third stage (III) consists in
controlling the selected policy, while watchdog variables are monitored.
Regular updating of the policy is foreseen, but watchdog variables may signal
shorter-term interventions.
Stage III is
important in order to verify on a current basis that no undesirable system
evolution occurs. The ASMC framework has been used to address important issues
in sustainable energy management.
4. Conclusions
Instruments
of systems thinking help very much in getting insight into the sustainability
rules of human systems. All private and public managers know that governing
staffs, or citizens, is an arduous task. Sustainability rules, in complex,
nonlinear, adaptive, self-organising systems must be elaborated. Managing such
complex living systems with emergent properties, and long-term consequences of
present actions, is extremely difficult when compared to engineered systems. It
requires a lot of insight into the way complex systems react to external
influences. Often the managers' intuition is not enough, because complex
systems behave in counter-intuitive ways, because of nonlinear feedback loops
manifesting emergent properties.
In order to avoid unsustainable decisions
the use of systems techniques by decision-makers and managers must be
reinforced. While flagship techniques remain System Dynamics (SD), Multi-Agent
modelling, and Network modelling, there is also a strong need for further
developing methodological approaches to complex nonlinear systems. This is the
reason why all papers presented in the Session "Methodologies in Complex
Systems" at the Bonn EURO XXIII Conference should be integrally published in
special issue.
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