According to wikipedia, DYMAMO “is a historically important simulation language and accompanying graphical notation developed within the system dynamics analytical framework. The first system created was called Dynamo. It is possible to create simple simulations without any understanding of the mathematics behind such models. The system dynamics group invented a way to represent differential equation in a way that is very accessible to novices. The behavior is due to the influences of food supply, predators, and environment, which are all elements of the system.
In the ecosystem example, the behavior is described by the dynamics of population growth and decline. The way in which the elements or variables composing a system vary over time is referred to as the behavior of the system. System dynamics is a methodology used to understand how systems change over time. A dynamic system is therefore a system in which the variables interact to stimulate changes over time. If something is dynamic, it is constantly changing. The term dynamics refers to change over time. The structure of the ecosystem includes the variables important in influencing the system. The structure of an ecosystem is defined by the interactions between animal populations, birth and death rates, quantities of food, and other variables specific to a particular ecosystem. One familiar example of a system is an ecosystem. The underlying relationships and connections between the components of a system is called the structure of the system. In the field of system dynamics, a system is defined as a collection of elements that continually interact over time to form a unified whole.