Case Study: Car Rental System

This case study illustrates the requirements gathering and definition process for a car rental system.

**Narrative:**

The car rental system operates similarly to real-world businesses like Enterprise, Budget, Hertz, and National. Customers can reserve a vehicle by calling ahead or using the company's website. Some customers may visit the rental office and rent a car on the spot, depending on availability.

Upon making a reservation, a confirmation number is provided to the customer. When picking up the vehicle, a Customer Service Representative (CSR) prepares a rental agreement. This agreement includes customer information (like the driver's license), vehicle details (VIN, model, make, color, license number, and current mileage), and rental duration details (return date, alternate drivers, free kilometers allowed, and pricing). Optional insurance coverage is also discussed.

After preparing and signing the rental agreement, the CSR and the customer inspect the vehicle to note any pre-existing scratches or blemishes. This ensures the customer is not held liable for prior damage. The customer receives a copy of the rental agreement, authorizing them to operate the vehicle.

Upon returning or dropping off the vehicle, the CSR retrieves the rental agreement and performs an inspection. The odometer reading is recorded, fuel tank level checked, and both exterior and interior are inspected for damage beyond what was initially noted. The bill or invoice is then calculated and presented to the customer for payment. Retail customers usually pay by credit card, and these details are noted on the rental agreement. Corporate account customers sign the bill, and a corporate invoice is generated monthly and sent to the head office's accounts payable department.

Once the vehicle is returned to the storage parking area, it is marked as "Returned-Service" in the vehicle inventory file. It is then cleaned and serviced to be made "available" for the next rental. However, if the vehicle's odometer exceeds 20,000 km, it is taken "out of service" and held "For Auction" until sold. This is standard policy, as customers prefer to rent new vehicles. Once sold at auction, the vehicle is removed from the inventory file.

If a vehicle is damaged upon return, it is repaired and then made "available" for rental again, noted in the inventory records.

**Use Case Diagram:**

- Include steps for all use cases.
- Add at least one alternative scenario to one of the use cases.