Requirements of Elevator System

An Elevator System is a complex real-time control application that operates between hardware (elevator motors, sensors, doors) and software (control logic, scheduling, UI). When designing its requirements, we must think about both functional and non-functional aspects to ensure safe, efficient, and user-friendly operation.

1. Functional Requirements

These describe what the system should do in response to different events and inputs.

• Request Handling:
  The system must accept elevator requests from both inside the cabin (floor selection buttons) and from outside on each floor (up/down call buttons).

• Movement Control:
  The elevator should move up or down to the requested floors in an optimized and safe manner, following scheduling logic.

• Door Operations:
  Automatically open and close doors at the destination floor, ensuring safety sensors prevent closing if an obstruction is detected.

• Floor Display and Indicators:
  Show the current floor, direction of movement, and elevator status on digital display panels both inside and outside the elevator.

• Alarm and Emergency Button:
  Allow passengers to trigger an alarm in emergencies; the system must respond by alerting building security or emergency services.

2. Non-Functional Requirements

These define how the system performs its functions, focusing on performance, reliability, and usability.

• Response Time:
  The elevator should process button requests and respond within 1–2 seconds for better user experience.

• Safety and Compliance:
  The elevator must comply with building safety standards, including overload prevention, fire protocols, and emergency stop.

• Availability and Uptime:
  The system must be available and operational 99.9% of the time, with minimal downtime for maintenance or failure.

• Scalability:
  The system should support multiple elevators working in coordination (e.g., in a high-rise building with 4–6 elevators).

• Energy Efficiency:
  The movement scheduling should reduce power consumption by avoiding unnecessary travel and idle time.

3. Hardware Interaction Requirements

Because an elevator system is partly embedded software, it must interact with various hardware components:

• Sensors: Detect current floor, door state (open/closed), and overload.
• Motors: Control vertical movement of the elevator.
• User Interface Components: Buttons, displays, speaker systems, and alarms.

4. System Management Requirements

For operations and monitoring by administrators or maintenance personnel:

• Logging and Diagnostics:
  Record elevator events such as movement logs, request patterns, and fault detection.

• Remote Monitoring:
  Allow system administrators to view elevator status, alerts, or failures remotely.

• Manual Override Controls:
  For maintenance or emergencies, staff should have the ability to operate the elevator manually.