Case Study Of conceptual Data and Logical Modeling
Realize a conceptual data and logical modeling for this case study
A Sales Department has a file of products that they provide to their customers. Each type of product has a unique product number, as well as a description, a cost and a price. The number of the product in stock and the number allocated are updated regularly. When the number in stock decreases to the reorder level, the product is reordered in a pre-decided quantity. The other operations of the Departments can be described as follows:
1. They have a file of customers. Each customer is given a unique customer number. This file also contains customer names that consist of their first and last names, and customer addresses composed of street, city and postcode and the customer telephone number. Each customer has a credit limit, which is used to validate their orders.
2. A customer may place zero, one or more orders at a time, and an order is always placed by one customer alone. Each order is identified by a unique order number. Other information as to orders includes the date due, the total price, and the status, that is, an order may be outstanding, partially delivered, or fully delivered and invoiced.
3. An order may involve one or more than one type of products, and a type of products may be involved in more than one order. For each product being ordered in an order, its quantity, total price, and status (i.e., outstanding, partially delivered, or fully delivered) are recorded and updated regularly.