This book contributes to several Operations Research fields, namely, global optimization, multiobjective optimization and location science. Reliable methods both for single and bi-objective optimization problems are developed. They are branch-and-bound algorithms which make use of interval analysis tools. Thus, they can be applied to (nearly) any optimization problem. To prove their applicability, new planar competitive facility location problems introduced in this book have been solved with them. Competitive location deals with the problem of locating facilities to provide goods to the...