Adding to the aforementioned discussions, we see many other
opportunities for future research. Overall, Table 2 shows that little
work has been carried out on integrating asset management in
SND problems, while in multimodal transportation, especially in
containerized shipment, more than one type of loading units are
involved, and repositioning their empties is costly. Furthermore,
these assets require simultaneous allocation planning. As an example,
crew scheduling is usually studied independently, but it also
depends on the service schedules, and embedding it in SND problems
is expected to provide higher performance efficiency.