2.6 THE NEED FOR STRUCTURAL BUILDING BLOCKS—MODULES

There are many occasions when working as a teacher or consultant, I have been called upon to demonstrate quickly and definitively how particular dynamic behaviour may have been produced. Most frequently such demonstrations are needed to support statements of hypotheses about dynamic behaviour, its causes and effects that we create as we travel along our journey of discovery and understanding of complex, real-world behaviour.

So often, I found myself searching for models or functional model building blocks, that I call modules in this book. In instances where I had thought about it in advance, I created these modules and demonstration models to have them ready when needed. Otherwise I would grab examples from models I had built for some other purpose. Having these models or modules close at hand demands more than being highly organised; it demands having an understanding of which ones might be needed most, and why.

As the reader will discover, if she or he has not already done so, there are certain feedback structures that continually and repeatedly re-appear because they are the building blocks of dynamic behaviour. In this book, these building blocks are identified as the ones we seek most to describe and classify as system dynamics modelling [common] modules.

To exploit these building blocks fully is a challenge that demands more than focusing on the building of archetypical models. A related challenge involves developing the skills to be able to dissect rapidly problem situations into inter-linked sets of building blocks that, in combination, produce the observed dynamic behaviour or reference modes of behaviour associated with a specific dynamic problem.