The Transportation Model Dialog allows several variations on
the simple transportation model. The checkboxes Include Minimums,
Include Maximums and Include Multipliers cause the
Add-in to build tables that allow the entry of minimum transportation
flows, maximum transportation flows, and arc gain factors respectively.
The Integer Flows box, adds the requirement that the
solution maintain integer flows.
The matrices for the example with arbitrary values
of lower bounds, upper bounds and gains are shown below. Lower
bounds represent minimum shipments along certain routes, while
upper bounds represent shipping capacities. When the gain factors
are other than one, the amount shipped on a link is not the
same as the amount received. The multipliers shown below represent
a loss, perhaps due to spoilage.