One of the main challenges of Healthcare services is to find a suitable way of managing limited resources within a highly demanding environment. This challenge can now be tackled by deploying reliable software systems that are supported by Software Engineering practices. In this paper, we present a Model Driven Engineering (MDE) approach that, by way of an example, is applied to an Accident and Emergency (AE) department. This approach works by designing a UML class diagram annotated with a set of OCL constraints. These constraints formally express restrictions on interactions between various elements of the system. We formally evaluate our model by using a logic solver. This approach lays the foundation of our intentions to further develop a more complete health care system. We report the valuable lessons learnt from the work and explain the limitation we observed.