
Transportation Models 349
23.4.1 General Form of Model
A transshipment point can be considered both, a supply point and a demand point.
At a transshipment point, k, the total quantity of product shipped to this point must
equal the total quantity of the product shipped from this intermediate point and can
be expressed as follows:
i=m
∑
i=1
x
i,k
=
j=n
∑
j=1
x
k, j
Where m is the number of supply points, n is the number of demand points, and
x
i j
is the amount of the product shipped from supply point i to demand point j. From
the previous equation, the transshipment constraint of a point, k, is expressed as
follows:
i=m
∑
i=1
x
i,k
−
j=n
∑
j=1
x
k, j
= 0 (23.1)
23.4.2 Transshipment ...