E-cha Enterprise requires an information system that able to manage and store their various type of lights, fans and air conditioner detail information such as product description, brand, model, serial number, date acquired, purchase price, as well as warranty expired date.

The products are supplied by a supplier. The supplier information such as supplier's name, address and company number must be stored in the database.

Each product has an employee that handles it and an employee can handle many products or may not manage at all. Employees are divided by two categories which are management and technician. The requirement for the system includes the details of employee information such as name, position, date of birth, address and telephone number.

The product such as air conditioner has many maintenance records. Maintenance information involves the maintenance's description and maintenance date. Product maintenance is done by the company technician. A technician is able to make many maintenance works. The qualification of technician must be stored in the system.

CREATE ERD/EERD based on the selected case study.