Database Analysis and Design (ER diagram)

After the requirement collection and analysis phase the software project of a database application about a company is described as follows:

1. The company is organized into departments. Each department has a name, an unique number, and a particular employee who manages the department. We keep track of the start date when the employee began managing the dept. A dept may have several locations.

2. A dept controls several projects, each of which has a name, unique number, and single location.

3. We store each employee's name, SSN, address, salary, gender, and DOB. An employee is assigned to one dept but may work on several projects, which are not necessarily controlled by the same dept. We keep track of the number of hours per week that an employee works for each project. We also keep track of the direct supervisor of each employee.

4. We want to keep track of the dependents of each employee for insurance purpose. We keep each dependent's first name, gender, DOB, and relationship to the employee.

Draw the E-R diagram by Dia tool.

Reference: Fundamentals of Database System, 3rd ed., by Elmasri