Self Supported System, as the name of it suggests, is supported by itself as a building together with side and roof cladding. It does not need to build walls and roof as needed for conventional warehouses. Self Supported System is consists of Racks, making the whole building.
In this case you can economy around 18%-27% of total cost comparing with ordinary system: constructing a building and purchasing racking system. There are no building columns inside of such system which allows using maximum horizontal space.