As the routing problem is computationally very demanding
(belonging to the set of NP-Hard problems), and cannot be solved
by optimal (exact) methods for large practical systems, heuristics
(e.g. Nearest Neighbour Insertion, Giant Tour based algorithms or
Clarke & Wright’s Savings algorithm) and meta-heuristics (e.g.
Ant Colony algorithms, Tabu Search, Simulated Annealing or
Genetic algorithms) are used for this purpose yielding an
as-optimal-as-possible solution (Laporte et al., 2000). For example,
Kuo and Wang (2011) proposed a method for solving the VRP minimizing
the fuel consumption applying Tabu Search to optimize the
routing plan