Valutazione Interna Uff. We consider the class of fixed-charge, multicommodity, capacitated network design formulation. These models represent a wide gamut of significant applications, but are difficult to solve. We describe a Tabu Search method that explores the continuous path flow solution space. Moves are based on pivot principles and are evaluated by using both fixed and variables costs.
Column generation is used to enlarge the neighbourhoods.
Long term memories recording the frequency of arcs in the best solutions are used to perform diversification moves. We also present a cooperative parallel strategy for these problems. Time permitting, we will briefly describe an alternate sequential tabu search strategy that explores the solution space of the discreet variables by using flow deviation moves along improving cycles.