Using Generic Structures in System Dynamics Model Building: Reflection from Modeling for Indian Shrimp Industry

Abstract

The paper focused on how a system dynamics modeler could reduce model development and testing time by using “Generic Structures” as an interim benchmark between causal loop diagram and stock flow diagram. Using generic structures as a benchmark could prevent the modeler from including redundant structures to the model and getting affected by personal biases that in turn could reduce repetitive amendments to the model during model testing. Indian Shrimp Industry, during 1990–2010, sequentially showed an early growth, a hasty decline, a combative rejuvenation, and an inexorable re-decline behavior in terms of the annual shrimp production and production capacity. Average Yield continuously fluctuated throughout the Industry’s life cycle during 1990–2010. Breaking such progressive behavior into temporal units, we found that the unit behaviors resemble with the behaviors of generic structures like, exponential growth, goal-seeking, S-shaped growth, limits to success, and overshoot-and-collapse. We, using the related generic structures as the interim benchmarks, illustrated a step-by-step modeling exercise for studying the dynamic behavior of Indian Shrimp Industry during 1990–2010. The paper concluded that using generic structures as the benchmark during system dynamics modeling improved the efficiency and the effectiveness of model building due to reduction in model building and testing time.