Design a Shared Car Rental System Using OOD Concepts

Shared Car Rental System Design Using Object-Oriented Design (OOD)

Designing a Shared Car Rental System requires considering the real-world entities involved in the rental process, such as vehicles, users, rental transactions, and payment management. The Object-Oriented Design (OOD) principles allow us to break down these components into manageable objects, ensuring flexibility and maintainability of the system. Below is an outline of the classes, their relationships, and their responsibilities.

Key Components:

1. User

2. Vehicle

3. RentalTransaction

4. Payment

5. Booking

6. CarMaintenance

7. Location

8. Review

9. Notification

1. Class Diagram

pgsql
CopyEdit
+----------------+       +-------------------+       +-------------------+
|     User       |<>---->|    Booking        |<>---->|   RentalTransaction|
+----------------+       +-------------------+       +-------------------+
| - userId: int  |       | - bookingId: int  |       | - transactionId: int|
| - name: string |       | - user: User      |       | - booking: Booking  |
| - email: string|       | - vehicle: Vehicle|       | - payment: Payment  |
| - phone: string|       | - startDate: Date  |       | - rentalDate: Date  |
| - address: string|      | - endDate: Date    |       | - endDate: Date     |
| - creditCardInfo |     | - location: Location|     | - totalAmount: float|
+----------------+       | - totalPrice: float|       +-------------------+
                        +-------------------+                
                                |
                                |
                     +--------------------+       
                     |     Vehicle         |
                     +--------------------+
                     | - vehicleId: int    |
                     | - make: string      |
                     | - model: string     |
                     | - year: int         |
                     | - availability: bool|
                     | - pricePerDay: float|
                     | - location: Location|
                     +--------------------+
                                |
                          +---------------------+
                          |    CarMaintenance   |
                          +---------------------+
                          | - vehicle: Vehicle  |
                          | - serviceDate: Date |
                          | - maintenanceDetails: string |
                          +---------------------+
                                |
                     +---------------------+
                     |    Payment          |
                     +---------------------+
                     | - paymentId: int    |
                     | - paymentDate: Date |
                     | - paymentMethod: string |
                     | - amount: float     |
                     | - transaction: RentalTransaction |
                     +---------------------+
                                |
                     +---------------------+
                     |     Review          |
                     +---------------------+
                     | - reviewId: int     |
                     | - user: User        |
                     | - rating: int       |
                     | - comment: string   |
                     | - vehicle: Vehicle  |
                     +---------------------+
                                |
                     +---------------------+
                     |    Notification     |
                     +---------------------+
                     | - notificationId: int|
                     | - message: string   |
                     | - user: User        |
                     | - dateSent: Date    |
                     +---------------------+

2. Class Descriptions

2.1. User

• Attributes:

  • userId: A unique identifier for each user.

  • name: The name of the user.

  • email: Email address.

  • phone: Contact number.

  • address: Physical address.

  • creditCardInfo: Payment method used for transactions.

• Responsibilities:

  • Registers as a new user.

  • Makes bookings for car rentals.

  • Reviews rented vehicles.

  • Receives notifications for booking updates, promotions, etc.

2.2. Vehicle

• Attributes:

  • vehicleId: A unique identifier for each car.

  • make: The manufacturer of the vehicle (e.g., Toyota, Ford).

  • model: The model of the vehicle (e.g., Corolla, Mustang).

  • year: The year of manufacturing.

  • availability: A boolean flag indicating if the car is available for rent.

  • pricePerDay: The rental price per day.

  • location: The current location of the vehicle (could be a GPS coordinate or physical address).

• Responsibilities:

  • Tracks availability and location of the vehicle.

  • Calculates rental price based on rental duration.

  • Records vehicle maintenance history.

2.3. Booking

• Attributes:

  • bookingId: Unique identifier for each booking.

  • user: A reference to the User who made the booking.

  • vehicle: A reference to the Vehicle being rented.

  • startDate: The start date for the rental.

  • endDate: The end date for the rental.

  • totalPrice: The total cost of the rental (calculated based on days rented and price per day).

• Responsibilities:

  • Stores the booking details.

  • Calculates the total rental price.

  • Manages the duration of the booking.

2.4. RentalTransaction

• Attributes:

  • transactionId: Unique identifier for the rental transaction.

  • booking: A reference to the associated Booking object.

  • payment: A reference to the associated Payment object.

  • rentalDate: The date when the rental begins.

  • endDate: The date when the rental ends.

  • totalAmount: The total amount charged for the rental.

• Responsibilities:

  • Links the booking with the corresponding payment.

  • Manages the transaction lifecycle (start and end dates).

2.5. Payment

• Attributes:

  • paymentId: Unique identifier for each payment.

  • paymentDate: Date the payment was made.

  • paymentMethod: The method used for payment (e.g., credit card, PayPal).

  • amount: The amount paid.

  • transaction: A reference to the associated RentalTransaction.

• Responsibilities:

  • Processes payments and records payment details.

  • Handles different payment methods.

2.6. CarMaintenance

• Attributes:

  • vehicle: A reference to the Vehicle that is undergoing maintenance.

  • serviceDate: The date of maintenance.

  • maintenanceDetails: Detailed description of the service performed.

• Responsibilities:

  • Keeps track of vehicle maintenance and service history.

  • Ensures the vehicle is safe for rental.

2.7. Location

• Attributes:

  • locationId: Unique identifier for the location.

  • address: The address or GPS coordinates of the car’s location.

• Responsibilities:

  • Manages the locations where vehicles are available for rent.

  • Tracks the movement or relocation of vehicles.

2.8. Review

• Attributes:

  • reviewId: Unique identifier for each review.

  • user: A reference to the user who left the review.

  • rating: Rating given by the user (e.g., 1 to 5 stars).

  • comment: Textual feedback.

  • vehicle: A reference to the vehicle being reviewed.

• Responsibilities:

  • Allows users to leave feedback about their rental experience.

  • Provides feedback to other users and car owners.

2.9. Notification

• Attributes:

  • notificationId: Unique identifier for each notification.

  • message: The content of the notification.

  • user: A reference to the user who receives the notification.

  • dateSent: The date the notification was sent.

• Responsibilities:

  • Sends notifications related to booking status, promotions, and vehicle availability.

3. Relationships and Interactions

• User ↔ Booking: A user can make many bookings, but each booking is made by only one user.

• Booking ↔ Vehicle: Each booking is associated with a single vehicle, but a vehicle can be booked multiple times.

• Booking ↔ RentalTransaction: Each booking is linked to one rental transaction.

• RentalTransaction ↔ Payment: A payment corresponds to a rental transaction.

• Vehicle ↔ CarMaintenance: A vehicle may have multiple maintenance records.

• Vehicle ↔ Review: Users can review vehicles after renting them.

4. Use Case Scenario

1. A User registers on the platform.

2. The User searches for available Vehicles in their location and selects one.

3. The User books the Vehicle for a specific period.

4. The system generates a Booking record and calculates the total price.

5. The User makes a Payment through a payment method.

6. Once payment is confirmed, a RentalTransaction is created.

7. After the rental period ends, the User can provide a Review for the Vehicle.

8. If any maintenance is required, the system schedules a CarMaintenance record for the Vehicle.

Conclusion

This design breaks down the Shared Car Rental System into key entities and encapsulates each aspect of the process using Object-Oriented principles. It ensures that the system is modular, maintainable, and scalable as the platform grows and the number of vehicles, users, and transactions increase.