Parallel processing for difficult combinatorial optimization problems

In identifying the general algorithmic problems most frequently encountered in designing and analyzing parallel algorithms (compatibility with machine architecture, choice of suitable shared or distributed data structures, compromise between communication and processing, and load balancing), we present recent research which has been carried out into parallelization of exact search methods such as Branch and Bound. We cover the main problems encountered with such a parallelization and present some theoretical and practical achievements in this field. The parallelization of heuristic search methods is shown to raise the same kind of issues.