Central to both types of algorithms is an orderto-route closeness metric, which defines the order addition rule in the seed algorithms and the combination rule in the saving algorithms. Table 5 summarizes closeness metrics proposed in the literature.
The seed and savings algorithms proposed inthe literature are similar in terms of their general procedure, but differ in the closeness metric used. Table 6 shows the different algorithms and the closenessmetrics they used as shown by the bold number after each citation.