Design EERD modeling that applies the following constraints, A relational database is to be designed for a large sized Car manufacturing and rental Company. The information required includes a description of cars, customers, company employees. The company employees could be described by such data as , Employee name , ssn , address, phone and their job type. There are three types of employees there, sales person who buy or sells cars with customers, mechanic who responsible of car maintenance tasks and the traditional employee who responsible on day to day activates. The DB should register the available worked hours for each sales person and his experience grade, also the mechanic we want to keep tack data about his technical grade. Cars are to be described by such data as: make, model, year of production, engine size, fuel type, number of passengers, registration number, purchase price, purchase date, and price. Each client has specific name and ID number and keep data about his phone, and address. All major repairs and maintenance tasks are done by company Mechanic and should be registered job repair file that contains data about job description, car number, and the repairing cost which may be cost for new part or cost for maintenance only.