Please draw an EER diagram based on the business rules below. Your EER diagram must be complete, meaning all necessary information must be presented. You must use the standard notations which we have used in the class. Underline the identifier for each entity. Make appropriate assumptions, if necessary, and clearly state them. The appropriateness of your assumption will be evaluated.



The ABC research center has multiple research labs which conduct a wide range of research projects.


Attributes of a research lab are LAB_ID (identifier) and location. Attributes of a project are Project_ID (identifier) and description. Each lab works on at least one research project. However, a research project can only be done in one research lab.


Many persons work at the ABC research center. A person could only be either a researcher or a technician. A person must be at least one of these categories. All person entities in the database have data provided their SSN, name and Phone number.


Each researcher must additionally provide Rank and Certificate as attributes. Each technician must additionally provide license number and restriction as attributes.


A researcher may be assigned to one project, many projects, or no project. A project must have at least one researcher assigned to it. The ABC researcher center want to keep track of the start date and end date of each employee-project assignment.


A researcher may or may not borrow some devices to conduct their activities. A device must be borrowed by only one researcher at a time. Attributes of device are Device_ID, Device_Name and Description. If a researcher borrows a device, you must record the borrow date and borrow time.


A technician performs maintenance on a device. A technician can perform maintenance on many devices as the need arises and a device when maintained needs at least one technician working on it. If a technician performs maintenance on a device, you must record the maintenance date and time