There are two aspects of unitisation of physical loads and these are palletisation and containerisation. Both palletisation and containerisation serve to reduce damage to agricultural and food products whilst these are in transit, and to increase the efficiency of the distribution system as a whole.
In international trade, there is a widespread adoption of a standard pallet size of 100cm × 120cm. Any exporter who ignores this standard when trading with countries that have adopted the standard will probably incur additional costs because of the need to repalletise the load. The argument in favour of a standard pallet size is simply that the operations of each of the parties in the physical distribution system will be more efficient if they all work to a common pallet size. Ships, lorries, rail freight cars, aircraft holds and warehouses can be designed to handle the standard pallet size and achieve maximum utilisation of space15.
The introduction of trailer size containers has allowed various forms of transportation to integrate their services since these units are interchangeable between different modes of transport. Containerization has made possible the transfer of loads between ships direct on to road and rail-based carriers and, of course, between road and rail. The main advantages of containerisation are the minimisation of damage to the goods, little or no pilferage and handling times reduced to 50 percent of those achieved with other systems.