Simulation models are designed to help policy makers, stakeholders, NGOs, researchers, and others to look at possible future development paths which are based on alternative and various development assumptions.
Simulations are conducted using models developed in either Vensim or Powersim - both of which are modeling languages. In order to develop a model / simulation which is both valid and reliable, it is necessary to understand Systems Theory and cause-effect mechanisms.
I have developed various models over the years, particularly focusing upon population demographics, AIDS epidemiology, water supply, land use, sustainable development and organisational structuring.
I also have substantial experience in scenario planning, data mining and knowledge discovery. All these skills are vital in helping top management to better understand cause / effect in chaotic, complex environments.
I use a Systems Dynamics approach to modeling. System
Dynamics is a method for studying the world around us. The central
concept to system dynamics is understanding how all the objects in a
system interact with one another. A system can be anything from a
steam engine, to a bank account, to a rugby team. The objects and
people in a system interact through "feedback" loops, where
a change in one variable affects other variables over time, which in
turn affects the original variable, and so on.
Systems Dynamics attempts to understand the basic
structure of a system, and thus understand the behaviour it can
produce. Many of these systems and problems can be built as models on
a computer. System dynamics takes advantage of the fact that a
computer model can be of much greater complexity and carry out more
simultaneous calculations than can the human mind.
The Systems Dynamics approach is not a new one
and has been used with great success in a number of environments and
industries. The model which emerges from an SD approach is:
- Much more flexible, reliable and valid than a model developed using traditional tools such as excel
- Allows participants in the modeling process to better understand the variables and system being modeled
Allows deep insight into the behaviour or and
interactions between the system components.
Systems Dynamics Approach
The following encompasses my approach to the
1. Task Definition – A Broad Description of the modeling task and its major components, variables and subsystems
2. Component Behavious Definition – This identifies the key variables in the system and plots their behaviour over time
3. Focus – this will involve the creation of a focusing statement for the project
4. Structure identification & Modeling – this involves a deep study and basic systems modeling of the system under study. When the model starts to behave like the system under study, we may then assume that our model has become more reliable and more valid.
5. Intervention planning – Once the model has been developed (step 4) we may then start to simulate variuous policy decisions using the model