Creating Entity-Relationship Model

Automata, Inc. produces specialty vehicles by contract. The company operates

several departments, each of which builds a particular vehicle, such as a

limousine, a truck, a van, or an RV.

• Before a new vehicle is built, the department places an order with the

purchasing department to request specific components. Automata’s

purchasing department is interested in creating a database to keep track

of orders and to accelerate the process of delivering materials.

• The order received by the purchasing department may contain several

different items. An inventory is maintained so that the most frequently

requested items are delivered almost immediately. When an order comes

in, it is checked to determine whether the requested item is in inventory. If

an item is not in inventory, it must be ordered from a supplier. Each item

may have several suppliers.

• Given that functional description of the processes encountered at

Automata’s purchasing department, do the following:

a) Identify all of the main entities.

b) Identify all of the relations and connectivity among entities.

c) Identify the type of existence dependence in all the relationships.

• Give at least two examples of the types of reports that can be

obtained from the database.