Designing A Hospital Inventory Management System
[A CASE STUDY OF UNIVERSITY OF IBADAN HEALTH SERVICES (JAJA CLINIC)]

E – R diagram
An entity-relationship diagram is a data modeling technique that creates a graphical representation of the entities, and the relationships between entities, within an information system. It depicts a visual representation of different data using conventions that describe how these data are related to each other.
The ER model is based on the following components:
i.    Entity: an entity can be defined as anything about which data are to be collected and stored. An entity is represented in the ERD by a rectangle, also known as an entity box. The name of the entity, a noun, is written in the center of the rectangle. The entity name is generally written in capital letters and is written in the singular form. The entities used are Students/Staff and Drugs.
ii.    Attributes: Attributes describes particular characteristics of an entity. They are usually represented by an oval shape. The attributes of the entities are: Students/Staff-Card Number, Name (First Name, Last Name, Other Names), Matric Number/ PF Number, Hall of Residence / Address, Phone Number, Date of Birth. Drug-drugName, drugType (Syrup, Tablet).
iii.    Relationship: Relationships describe associations among data. Most relationships describe associations between two entities. When the basic data model components were introduced, three types of relationships among data were illustrated: one-to-many (1:M), many-to-many (M:N), and one-to-one (1:1). The ER model uses the term connectivity to label the relationship types. The name of the relationship is usually an active or passive verb. The relationship between the two entities is collects, with attributes date and Quantity.