Multiple elevator coordination in LLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main goal of multiple elevator coordination?

To efficiently manage multiple elevators so that they serve passenger requests quickly and fairly, minimizing wait and travel times.

beginner

Name one common strategy used in multiple elevator coordination.

The 'Nearest Car' algorithm, which assigns the elevator closest to the requested floor to serve the call.

intermediate

Why is load balancing important in multiple elevator systems?

Load balancing prevents some elevators from being overused while others stay idle, improving overall system efficiency and reducing passenger wait times.

intermediate

Explain the role of a centralized controller in multiple elevator coordination.

A centralized controller collects all elevator and request data, then decides which elevator should respond to each call to optimize performance.

advanced

What challenges arise when coordinating multiple elevators in a tall building?

Challenges include handling many simultaneous requests, minimizing wait times, avoiding elevator conflicts, and managing different elevator speeds and capacities.

Which algorithm assigns the closest elevator to a floor request?

A Random Assignment

B Nearest Car

C Round Robin

D First Come First Serve

The Nearest Car algorithm chooses the elevator closest to the requested floor.

What is the main benefit of load balancing in elevator coordination?

A Increases elevator speed

B Reduces building height

C Prevents elevator overuse and reduces wait times

D Increases elevator capacity

Load balancing helps distribute requests evenly to reduce wait times and avoid overusing some elevators.

What does a centralized controller do in multiple elevator systems?

A Manages all elevators and assigns requests

B Controls only one elevator

C Repairs elevators

D Monitors weather conditions

A centralized controller manages all elevators and decides which elevator serves each request.

Which factor is NOT a challenge in coordinating multiple elevators?

A Managing elevator colors

B Avoiding elevator conflicts

C Minimizing passenger wait times

D Handling many simultaneous requests

Elevator colors do not affect coordination; the other options are key challenges.

Why might elevators have different speeds in a tall building?

A To save energy

B To confuse passengers

C Because of weather

D Due to design differences and mechanical limits

Elevators may have different speeds based on their design and mechanical capabilities.

Describe how multiple elevators can be coordinated to minimize passenger wait times.

Think about how to decide which elevator should answer a call.

List the main challenges faced when designing a multiple elevator coordination system for a tall building.

Consider what makes tall buildings complex for elevator systems.