Visual essay explores elevator scheduling algorithms
"Elevators" by John Herrick is an interactive visual essay exploring the mechanics and algorithms behind elevator dispatching systems, from simple SCAN and LOOK logic to multi-car heuristic coordination like Otis's Relative System Response algorithm. Through SVG simulations and wait-time distribution graphs, it demonstrates how re-optimization, load penalties, and anti-bunching rules impact efficiency across traffic regimes.
Systems engineering often reveals counterintuitive truths—such as how advanced multi-car heuristic scheduling like RSR can actually be outperformed by simpler SCAN/LOOK algorithms during extreme high-density traffic.
• Visual simulations provide an exceptionally clear breakdown of complex queueing and scheduling concepts like anti-bunching and dynamic car scoring.
• Demonstrates the importance of tail latencies (p90) over average wait times in designing human-centric automated systems.
• Highlights the real-time re-optimization trade-offs necessary when coordinating multiple autonomous agents in physical environments.
DISCOVERED
1d ago
2026-07-31
PUBLISHED
1d ago
2026-07-31
RELEVANCE
AUTHOR
Jrh0203