System Dynamics Applications / 2 / 2.10

2.10 MODULES TO DELIVER SPECIFIC FUNCTIONALITY

This book takes the system dynamics modelling experiences of Coyle (1996) and the initiatives of Hines, et al. (1996; 1997; 2000) and teaching of Sterman (2000) and defines the characteristics and functionality of system dynamics modelling modules for general use as building blocks for system dynamics models using Powersim^TM Studio. The products are sets of small modules through to complete models, which deliver specific functionality—that is, they replicate very specific dynamic behaviours.

Like a designer, builder, mechanic or engineer putting together the component parts of a building, a motor vehicle or code to control a machine, the system dynamics practitioner equipped with these modules and a clear understanding of how they work faces the exciting prospect of quickly and reliably building models that really work and in which they can have full confidence.

Any complex problem can be dissected and reassembled provided that we understand each of the component parts, how they fit together and know how to define and manage the interfaces between parts of the problem. Consider the following example. When a plumber installs new water pipes, he does not make connections to gas pipes or electrical cables or optic fibre cables because these are incompatible with water pipes, and do not carry water. Further, a 100-mm pipe cannot be connected to a 20-mm pipe with the expectation that flow will continue unchanged. In system dynamics modelling we must make all connections between physical flows or between information flows in ways that are consistent and make complete sense. We must have compatibility throughout.