Capacity planning is a fundamental activity that regulatory agencies in the public sector are called to carry out in order to improve the quality of services. Thus, there is an increasing need to understand how the capacity planning used under public sector would support activities of operational management from a dynamic perspective. In this article, System Dynamics (SD) modelling has been used for strategic capacity planning and policy analysis, supported by a dynamic performance management (DPM) approach. This model-based planning methodology, which has long been the main way of approaching planning in the public/private sector is supported by a novel performance management framework. The results show that institutions in the public sector should change from traditional planning to strategy development taking into account the response capacity in the services promised. The main contribution of this article is assessed the strategy resources for the public sector, with a regulatory agency of Colombia taken as a case study.