Activity Diagram – Car Parking 

The Activity Diagram for the Car Parking System represents the sequential flow of operations that a vehicle goes through when interacting with the system, from entering the parking lot to exiting after payment. It outlines the dynamic behavior of the system and how different actions are coordinated to complete the parking process.

Activity Flow Description

• Vehicle Arrives at Entry Gate
  The process begins when a vehicle approaches the entrance of the parking lot. This action triggers the system to start a new parking session.

• Check Slot Availability
  The system checks for vacant parking slots using sensors or a central database. If slots are available, the process continues. Otherwise, a message is displayed to the driver indicating that the parking lot is full.

• Generate Parking Ticket
  If slots are available, the system generates a parking ticket. This ticket may include the time of entry, slot number, and a unique identifier such as a barcode or QR code.

• Assign Parking Slot
  A specific parking slot is assigned to the vehicle. The driver is guided to the slot via digital signage or by an attendant.

• Vehicle is Parked
  The driver parks the vehicle in the assigned slot. The slot status is updated to ‘occupied’ in the system.

• Vehicle Arrives at Exit Gate
  When the driver returns, the vehicle approaches the exit gate to leave the parking area.

• Scan Ticket / Retrieve Entry Time
  The system scans the ticket or retrieves the entry time and details using license plate recognition. It calculates the total time the vehicle was parked.

• Calculate Parking Fee
  Based on the parking duration and pricing rules (e.g., hourly rates), the total fee is calculated.

• Payment Processing
  The user is prompted to pay the amount using one of the available payment methods (cash, card, digital wallet). Once payment is successful, a receipt is generated.

• Update System and Open Gate
  The system updates the parking status, marks the slot as ‘vacant,’ and opens the exit gate to allow the vehicle to leave.

• End of Activity
  The process ends when the vehicle exits the parking lot and the transaction is recorded in the system logs for administrative purposes.

Optional Parallel Activities

• Real-time Monitoring: Admin or security personnel can continuously monitor parking slot statuses.

• Reports Generation: Periodic reports about usage patterns, revenue, and slot occupancy can be generated in the background.