In this paper, we present a procedure Grounded System Dynamics (GSD) which we use as a guide to underpin a System Dynamics (SD) model with a domain modeling method called Object-Role Modeling (ORM). GSD is a combination of two existing methods (SD with ORM). By combining these two methods we generate synergy effects by using already existing modeling methods and by so doing we overcome some of the weaknesses of SD model building. Secondly, transformation of information from an ORM model of dynamic domains into an SD model is achieved. To apply the GSD procedure to a real-life case (Mukono Health Center (MHC), we use SD-ORM mapped constructs. As a result from the GSD procedure application, is an SD model to which we define quantitative foundations that result into simulations. Our approach(GSD) has been validated using case studies one of which is described in this paper. From this conclusions are drawn.