System analysis for environmental policy – System thinking through system dynamic modelling and policy mixing as used in the SimRess project

Diverse and complex interactions as well as multi-actor systems characterise resource use and re- source policy. This makes system analysis a relevant tool to orient resource policy towards the long term. Analysing such complex systems requires systemic thinking, consideration of causal loops as well as time-lags and delays in system responses.
In the SimRess project, system analysis encompassed participatory conceptual system modelling via involving external stakholders into identifying system boundaries and elements via causal loop dia- grams (CLDs). The CLDs were than reflected in the parametrisation of simulation models and the de- velopment of policy mixes.
Only a limited number of stakeholders participated in two of the five workshops needed for a fully- fledged group modelling process. Therefore, the project team finalised internally the conceptual sys- tem model. Although this reduced ownership and transparency of the system model, the two work- shops provided relevant system knowledge for further modelling work and policy mix development.
During policy mix development in SimRess, we needed to deviate from the theoretical concept of pol- icy mixing based on available project capacities and stakeholder decisions. On the one hand, under- standing and assessing cumulative effects of policy mixes challenged conceptual policy mix develop- ment and simulation capacities. On the other hand, stakeholder decisions impacted on the depth at which system analysis via simulation models could be undertaken.