Data Modeling with the Entity-Relationship Model James Morgan of Morgan Importing has decided to expand his business and needs to staff and support a...

Data Modeling with the Entity-Relationship Model

James Morgan of Morgan Importing has decided to expand his business and needs to staff and support a procurement system6 to acquire the items sold at Morgan Importing. Suppose that you have been hired to make and implement a database application to support a procurement information system. Data in this procurement information system will include:

6If you are not familiar with the concept of a procurement system, see the Wikipedia article on Procurement.

• The purchasing agents employed at Morgan Importing
• The receiving clerks employed at Morgan Importing
• The stores where the purchasing agents buy items
• The purchases themselves at the store
• The shippers used to ship the purchases to Morgan Importing
• The shipments made by the shippers
• The receipt of the shipments at Morgan Importing by the receiving clerks

James Morgan and his wife Susan often make purchases themselves while traveling to various countries (and, therefore, even though they are not purchasing agents per se, they need to be listed as purchasing agents in the system when data is entered). Purchases may be made at the stores themselves or by Internet or phone. Sometimes several items are purchased from a store on a single visit, but do not assume that all of the items are placed on the same shipment. Shipping must track each item in a shipment and assign a separate insurance value to each item. Receiving must track the arrival date and time of a shipment, who accepted receipt of the shipment on behalf of Morgan Importing, and the condition of each item upon receipt.

1. Make a data model for the Morgan Importing procurement information system. Name each entity, describe its type, and indicate all attributes and identifiers. Name each relationship, describe its type, and specify minimum and maximum cardinalities.
2. List any item in your answer to A that you believe should be checked out with James Morgan and/or his employees.