Simulated Annealing

How does it work?

Simulated Annealing methods search a space of candidate solutions. They typically define neighbor moves or gradients, evaluate objective functions, and use schedules or memory to escape local optima or to converge reliably.

Examples

  • VLSI placement — Optimise chip component layouts with a cooling schedule to escape local minima.
  • Traveling Salesman approximations — Find near-optimal tours via random neighbour moves and temperature-controlled acceptance.
  • Job-shop scheduling — Schedule tasks on machines by accepting worse moves early and reducing acceptance over time.

Problems

  • Designing an effective cooling schedule
  • Slow convergence relative to other metaheuristics
  • Sensitive, problem-specific tuning of the acceptance function
  • No guarantee of finding the global optimum in finite time
  • Hard to parallelize due to its sequential nature
  1. Wikipedia: Simulated annealing