Data models are tools used in analysis to describe the data requirements and assumptions in the system from a top-down perspective. Attributes are the data we collect about the entities.
Relationships provide the structure needed to draw information from multiple entities.
Usually each patient will be assigned a single doctor, but in rare cases they will have two. Heathcare assistants also attend to the patients, a number of these are associated with each ward. Initially the system will be concerned solely with drug treatment. Each patient is required to take a variety of drugs a certain number of times per day and for varying lengths of time. The system must record details concerning patient treatment and staff payment .