Bridging the Divide Between Systems Thinking and System Dynamics: Reconciling Qualitative Causal Loop Diagrams ( CLD ) and Quantitative System Dynamics Models on Common Defining Characteristics and a

ABSTRACT

In this research, we ask two questions at the heart of a longstanding divide. First, are qualitative systems thinking CLDs and quantitative system dynamics models, originating in separation and brought together only reluctantly, essentially the same? Qualitative and quantitative versions of a similar scientific method for studying phenomena in complex systems through abstractly represented models. Second, do they share a common set of defining characteristics and a shared order of structure? We believe the answer to both is yes. We explore the history of the divide and how it mapped to larger scientific debates between qualitative and quantitative methods characterized by shifting phases of disdain, détente, and cooperation. We distill our findings into a metaphor and an analogy. A metaphor of a bridge crossing the divide, anchored on either side by a common set of defining characteristics. And an analogy of how to build that bridge with rigor on a shared architectural order of structure. Our proposed reconciled order of structure lays a solid foundation for past and future efforts to address limitations of both methods, and we share five key insights in that regard. We also hope this work contributes to the continuing dialog of identity in our field.