Database System Development Life Cycle

 
After you have analyzed the existing material used by the company for their day-to-day duties, the current Access database, and the additional requirements that the current system does not meet, the following requirements entity/attributes have been compiled:

Customer information is tracked using ‘standard’ attributes.
A customer may purchase products or services; if they purchase products or services, the following is tracked:

Product purchased
Date of purchase
Total of purchase

A supplier may sell products or services; if they sold products or services, the following is tracked:

Product sold
Date of sale
Total of sale
Is item purchased available for resale

Your company wants to keep the number of tables storing address information to a bare minimum (read this as 1).
Customers can be both a “supplier” and “someone that purchased services,” and it is not required that they be either.
Employee information is tracked using standard attributes.
An employee will either be considered customer interfacing or internal support.
If the employee is customer facing, the following information is tracked:

Customer for interaction (note that a customer will only interface with a single employee)
Product specialty
Hours of training
Commission rate

If the employee is internal support, then the following is tracked:

Salary
Support area

An employee can be either customer facing or internal support, but not both.
Your company wants to keep the number of tables storing generic employee information to a bare minimum (read this as 1).
Finally, the company wants to track products or services offered. This should be a single table with typical attributes that describe inventory.
Every customer that either makes a purchase or sells goods to the company must be associated with an employee.
Every transaction that a customer makes with the company is stored/tracked, A customer may buy or sell many products, and a product is sold to more than one customer.

Create an enhanced ERD to meet these requirements. Ensure that entities are properly defined and appropriate attributes are listed for each entity. Also, ensure that all entities are properly related.
Add your ERD as a screenshot to a Word document, and provide supporting discussion about the need for the enhanced diagram tools and the reasoning behind the multiplicity for the relationships.
Add the enhanced ERD and the discussion about the relationship multiplicity to your project template to the section titled “Database System Development Life Cycle.”