Objective: To draw your Entity-Relationship Diagram and Enhanced Entity-Relationship Diagram by using the data modeling tool: Dia Diagram Editor using Chen Notation.

The COMPANY database keeps track of a companys employees, departments, and projects. Suppose that after the requirements collection and analysis phase, the database designers provide the following description of the miniworld the part of the company that will be represented in the database.

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

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

We store each employees name, Social Security number, address, salary, sex(gender), and birth date. An employee is assigned to one department, but may work on several projects, which are not necessarily controlled by the same department. We keep track of the current number of hours per week that an employee works on each project. We also keep track of the direct supervisor of each employee (who is another employee).

We want to keep track of the dependents of each employee for insurance purposes. We keep each dependents first name, sex, birth date, and relationship to the employee.

The employee type may be distinguished further into SECRETARY, ENGINEER, MANAGER, TECHNICIAN, SALARIED_EMPLOYEE, HOURLY_EMPLOYEE, and so on.

Design an EER diagram for the Company database based on the requirements above using Dia. Write down any assumptions you have made