Understanding Elevator Algorithms

Elevator algorithms are fascinating examples of everyday optimization problems. They need to balance multiple competing factors:

• Minimize average waiting time
• Minimize total travel distance
• Provide fair service to all floors
• Handle peak usage patterns efficiently

Common Algorithms

1. FCFS (First Come, First Served)

• Simplest approach: serve requests in order of arrival
• Can lead to inefficient “ping-pong” patterns
• Poor performance under heavy load

2. SCAN (Elevator Algorithm)

• Move in one direction until no more requests in that direction
• Then reverse direction and repeat
• Better handling of multiple requests
• Can lead to some requests waiting longer

3. LOOK

• Similar to SCAN but only goes as far as the last request
• More efficient than SCAN for most scenarios
• Default choice for many real implementations

Interactive Simulation

This simulation features an automated request generation system that simulates real-world elevator traffic patterns:

Traffic Patterns

• Morning Rush: Heavy upward flow from ground floor
• Lunch Time: Mixed traffic between all floors
• Evening Rush: Heavy downward flow to ground floor
• Random: Uniformly distributed requests

Simulation Controls

• Start/Stop the simulation
• Select traffic pattern
• Adjust request rate (15-120 requests/minute)
• Choose scheduling algorithm
• Max Capacity: Elevators have a maximum capacity of 8 passengers.
• Floor Pause: A brief pause at each floor to simulate door opening and closing.