Complex systems modeling of infrastructure assets, operators, users, and politicians using system dynamics

Traditional infrastructure asset management frameworks have focused on modeling the physical infrastructure asset. Infrastructure systems (IS) are a complex web of various physical and human elements that interact together to exhibit evolving behavior. This paper proposes the use of system dynamics (SD) modeling to represent the interactions that occur among physical infrastructure, system operators, infrastructure users and political decision makers. The proposed model considers; a) the assets' conditions, and deterioration rates, b) the operators' decisions and policies, c) the users' attitude and fees, d) the politicians' budget allocation decisions and political approval rates. Causal loop diagrams are developed to capture the relationships between these components and balancing / reinforcing loops are identified. An illustrative simulation example is presented to highlight how a change in the components of any of the four sectors under consideration, has a propagating effect through the other sectors. The developed SD simulation model can be used as a test bed to evaluate both short-term and long-term impacts of policy decisions on the goals of users, system operators and politicians.